ISSN 0308-0838

THE

FERN GAZETTE

VOLUME ELEVEN PART SIX

1978

THE JOURNAL OF THE BRITISH PTERIDOLOGICAL SOCIETY

THE

FERN GAZETTE

VOLUME 11 PART6 1978

CONTENTS Page

MAIN ARTICLES A tetraploid cytotype of Asplenium cuneifolium Viv. in Corisca

R. Deschatres, J.J. Schneller & T. Reichstein 343

Further investigations on Asplenium cuneifolium in the British I sles -

Anne Sleep, R.H. Roberts, Janet I. Souter & A.McG. Stirling 345

The pteridophytes of Reunion I sland -F. Badni & Th. Cadet 349

A new Asplenium from Mauritius - David H. Lorence 367

A new species of Lomariopsis from Mauritius- David H. Lorence

Fire resistance in the pteridophytes of Zambia - Jan Kornas 373

Spore characters of the genus Cheilanthes with particular reference to

Southern Australia -He/en Quirk & T.C. Chambers 385

Preliminary note on a fossil Equisetum from Costa Rica - L.D. Gomez 401

Sporoderm architecture in modern Azolla - K. Fowler & J. Stennett-Willson · 405

Morphology, a,natomy and taxonomy of Lycopodiaceae of the Darjeeling

Himalayas- Tuhinsri Sen & U. Sen. 41 3

SHORT NOTES

The range extension of the genus Cibotium to N ew Guinea - B.S. Parris 428

Notes on soil types on a fern-rich tropical mountain summit in Malaya -

A.G. Piggott 428

lsoetes in Rajasthan, India - S. Misra & T.N. Bhardwaja 429

Paris Herbarium Pteridophytes - F. Badre, 430

REVIEWS 366, 37 1 , 399, 403, 404

[TH E F E R N GAZETTE Volume 1 1 Part 5 was publ ished 1 2th December 1 977]

Publ ished by TH E B R I TI S H PTE R I DO LOG I CAL SOC I ETY, c/o Oepartment of Botany, British M useum (N atural H istory ) , London SW7 5BD.

F E R N GAZ. 1 1 (6) 1978

A TETRAPLOID CYTOTYPE OF ASPLENIUM CUNEI FOLIUM VIV. IN CORSICA.

R . D ESCHAT R ES Le Bois-Randenais, Brugheas, F-031 1 0 Escuro l l es

J .J . SC H N E L L E R l nstitut fUr Systematische Botan i k der Universitat,

1 07 Zo l l i kerstrasse, CH-8008 Zu rich & T. R E I C HSTEIN

lnstitut fUr Organ ische Chem ie der Universitat, 1 9 St. Johanns- R i ng, CH-4056 Base l

ABSTRACT

A tetraploid, morphologica l l y simi lar to Asplenium cuneifolium Viv . , is reported for the first time.

INTRODUCT I O N

343

Asplenium cuneifolium Viv. is a sma l l fern of the Asplenium adiantum-nigrum group so far known to extend from Portugal (P into da Si lva . 1 968) , throughout most of Europe (Crabbe, Jermy & Lov is, 1 964; Jalas & Suominen, 1 972, map 92) to Turkey (Henderson, 1 965) . lt grows exclusivefy on ultrabasic rocks (serpentine; perfdotite, magnesite) or m ixed rocks and screes conta in ing these mater ia ls . As in a l l other members of th i s group (A. adiantum-nigrum L., A. ondpteris L.,A. balearicum Shivas and A. pseudolanceolatum Fomi n ) , it is morphologica l ly a rather variable species and s ingle fronds cannot a lways be identified with confidence from herbar ium materia l . If more ample materia l is ava i l able, or if popu lations can be seen in the fiel d , correct identification is usua l ly easy.

Al l plants of A. cuneifolium from central and eastern Europe which have been checked so far ( Love, Love & Pich i-Sermo l l i, 1 977, p. 241 ) have been found to be diploid and sexual (n = 36, 2n = 72) and A. cuneifolium has been shown to be an ancestor of the a l lotetraploid Asplenium adiantum-nigrum (Sh ivas, 1 969) . I n 1 974, a pop u l ation g rowing on serpentine s . l . (green schists) in Corsica was detected by one of us ( R . D . ) . Progeny raised from spores in Basel (TR-3839) proved to be tetraploid. On the basis of gross morphology we are unable to d istingu ish these plants with confidence from the h itherto known d iploids, a lthough they do have bigger spores and poss ibly other d ifferences in micro-characters. We assume that they represent a tetraploid cytotype of essentia l ly autotetraploid origi n , which is not uncommon among other members of Asplenium ( Lovis , 1 964; Sleep, 1 966) , Phyllitis ( Emmott, 1 964) and Ceterach (V ida, 1 963) . Such essentia l ly autopolyploid cytotypes have frequently been d istingui shed from their d iploid ancestors as subspecies, and we intend to fo l low this procedure . Th i s treatment, however, is not entirely satisfactory si nce the category of subspecies was created for other pu rposes.

We refrain from suggesting any new subspeci fic name unt i l we can establ ish to which cytotype Viv ian i 's type of A. cuneifolium can be referred . Documentation with figures wi l l be publ i shed elsewhere. The spores used for raising the plants wh ich have been counted were col l ected by R. Deschatres in Corsica, between Sermano and Bustanico, 9th Ju ly 1 974. A tetraplo id cytotype has a lso been found in Scotland and Ire l and (Sleep et a l . , 1 978)" and may occu r in other loca l it ies. We are wi l l i ng to accept wel l pressed fronds with spores for identification.

*See p.345 of this issue

344 F E R N GAZETTE: V O L U M E 11 PA RT 6 (1978)

ACKNOWLEDGEMENT

We thank Dr. Anne Sleep and Mr. A. McG . Sti r l i ng for the i r kind co-operation.

R E F ER ENCE

CRABBE, J.A., JERMY, A.C. & LOV I S, J.D. 1 964. Asplenium in Flora Europaea I , Cambridge. EMMOTT, J . l. 1964. A cytogenetic investigation in a Phyllitis-Asplenii.Jm complex. New

Phytologist 63: 306-3 18. HEND ERSON, D.M. 1965 in DAV IS, P.H. Flora of Turkey I , Edinburgh. JALAS, J. & SUOM I N E N J. ( Eds), 1 972. Atlas FloraeEuropaeae 1. Pteridophyta, Helsinki . LO VE, A., LO V E D. & P I CH I S ERMO L L I , R . E.G. 1977. Cytotaxonomic Atlas of the

Pteridophyta, Vaduz. LOV IS, J.D. 1964: Autopolyploidy in Asplenium, Nature 203 (4942), 324-325. P I NTO DA S I LVA, A . R . 1968 : A flora e a vegetacao das areas u ltrabasicas do nordeste

transmontano. Subsidios para o seu estudo. Agron. Lusitana 30 (3-4) J 1 75-364 + VI tav. SH IVAS, M.G . 1969: A cytotaxonomic study of the Asplenium adiantum-nigrum complex. Brit.

Fern Gaz .. 10: 68-80. SLEEP, A. 1966: Some cytotaxonomic problems in the fern genera Asplenium and Polystichum.

Ph.D. thesis, University of Leeds. SLEEP, A., ROBERTS, R .H., SOUT E R , J. l . & ST I R LING, A. McG. 1978. F urther investigations

on Asplenium cuneifolium in the British I sles. Fern Gaz. 1 1: 345-348. VIDA, G. 1963: A new Asplenium (Sectio Ceterach) species and the problem of the origin of

Phyl/itis hybrida (Mi lde) C. Ch rist. Acta Bot. Acad. Sci. Hun.!l. 9: 197-2 1 5.

FERN GAZ. 11(6) 1978

FURTHER INVESTIGATIONS ON ASPLENIUM CUNEI FOLI UM IN THE BRITISH ISLES

A N N E S LEEP Department of P l ant Sciences, the Un iversity, Leeds LS2 9JT

R . H . ROBE RTS 51 Bel mont Road, Bangor, Gwynedd JAN ET I. SOU T E R (nee E M M OTT)

Department of P l ant Sciences the Un iversity , Leeds LS2 9JT & A.McG . ST I R L I NG

17 Austen Road, G lasgow G 1 3 1 SJ

ABSTRACT

Chromosome counts have been made from twenty collections of putative Asplenium cuneifolium from Scottish serpen tine l ocalities and a l l have proved to be un iformly tetraploid; with n = 72. l t is thought that these plants are identical with a tetraploid cytotype of Asplenium cuneifolium which has recently been described from Corsica.*

345

The d iscovery of a fern bel ieved to be morphologica l ly identical with the conti nental Asplenium cuneifolium Viv . was described by Roberts & Sti r l i ng ( 1 974) from several d ifferent serpentine local ities in Scotland. Three pl ants from two of these local ities (G len Lochay and G lendarue l , Argy l l ) were counted and gave d i plo id chromosome cou nts. Subsequently chromosome counts of plants from three more of the Scottish serpentine local ities were made in order to check the distr i bution of putative Asple'nium cuneifolium for the Atlas of Ferns of the British I s les (Jermy et a l . , 1 978) , which was, at that time, in preparation. Surpris ingly, every plant examined proved to be tetraploid, with n = 72. A s imi lar resu l t was obta ined from a plant of putative A. cuneifolium which was col lected from serpentine rocks at Dawross, Connemara, I re land, by A. Rutherford, M. Scannel l and A. McG . Stir l ing in Ju ly 1 975. Fol lowi ng these rather unexpected resu lts, the Scottish loca l ities from wh ich the original col l ections came were re-sampled during the summer of 1 977; sporangia! f ix ings were taken by A. McG . S. from the s ite� enumerated in Table I , and were sent to Leeds for cyto logical exami nation . In this re-i nvestigation, some twenty plants from e ight local ities have been exami ned cytologica l ly , and all have proved to be tetraploid (see Table 1). No diploids have been recorded. In v iew of the un i formity of these results, it seems that these popul ations of putative Asplenium cuneifolium from serpentine rocks in Scotland and I reland may genera l ly prove to be tetraploid.

As has been shown by Roberts & Sti r l ing ( 1 974), these Scott ish Asplenium populations are morphological l y d istinct from Asplenium adiantum-nigrum L. and are very s imi lar to the continental A. cuneifolium Viv. , a central European species characteristic of serpenti ne and other u l trabasic rocks. The speci mens of A. cuneifolium which have been exami ned cytological ly have been found to be diploid, with n = 36 ( Love, Love & Pichi- Sermo l l i , 1 977) . I n add ition, Sh ivas ( 1 956, 1 969) has shown this species to be one of the ancestors of A. adiantum-nigrum L. R ecently, a plant from Corsica, which one wou ld, on morphological grounds, h ave no hesitation in referri ng to A. cuneifolium Viv . , was counted, and proved to be tetrapl oid ( Deschatres, Schnel ler & Re ichstein, 1 978) . Th is plant cou ld be an autotetraploid derivative of the d i plo id cytotype of A. cuneifolium Viv. The spores of th is tetraploid

*See p.343 of th is issue.

346 FERN GAZET T E : V O L U M E 11 PA RT 6 (1978)

TABLE 1

LOCALITY COLLECTOR AND RESULT NO. CELLS NUMBER OBSERVED

Near Ben Bowie AMS/1 /77 n = c.70 2 (NS 347831 ) . Hf!lensburgh . vc 99. D u n barton. Lime H I L L (NS 473963) . AMS/2/77 n = 72 7+ *

Loch Ard Forest. vc 86. Sti r l ing .

AMS/3/77 n = c.70 1 0 4/75 n = c.70 2

Glendaruel (NS 021 904 ) . AMS/4/77 n = 72 7 vc 98. Argy l l .

AMS/5/77 n = 72 6 AMS/6/77 n = 72 1 0 AMS/7/77 n = 72 4

Corrycharmaig. Glen AMS/8/77 n = 72 4 Lochay ( N N 521 358) . vc 88. M id Perth .

AMS/9/77 n = 72 7 AMS/1 0/77 n = c.70 3 AMS/1 1 /77 Tetraploid 6

Balhamie H i l l . near 6/75 Tetraplo id 9 Colmone l l ( N X 1 33859) . vc 75. Ayr. Craigs of Succouth. 7/75 n = 72 6 Upper Deveron Val ley. Bridgend (NJ 400347 ) . vc 94. Banff.

J I S/76/8 n = 72 8 J I S/76/1 1 Probably 4

tetrap lo id J I S/76/ 1 2 Tetraploid 4 J I S/76/ 1 6 Tetraploid 3

Fetlar. vc 1 1 2. R .C . Pa lmer Tetraploid 8 Shetl and. Dawross. Con nemara. 2/75 Tetraploid 5 vc H 1 6. West Ga lway. Ireland.

FOOTNOTES TO TA BLE I

* 7+ indicates that unequ ivocal counts of n = 72 were obtained from 7 cel ls , but that other cel l s seen gave counts of a similar order.

n = 72. Precise and unequivocal counts were obtained from the cel ls l isted.

Tetraploid indicates that all ce l l s observed gave counts of tetraploid order.

S LEEP ET AL.: ASPLENIUM C U N E I FO L I U M IN THE B R I TISH ISLES 347

• a •

..

- � of • • A B

• • ... ...

tl..• . ••• , .

• ••

• ,. " '

• ., '

.. •

• • •

c .,. D

E F

G H F I GURE 1 . Photomicrographs of spore mother cells in meiosis of putative Asplenium cuneifolium from different Scottish loca l i ties . A-8, AMS/6/77 (Giendarue l , Argy l l ) diakinesis , both showing n =

72; C, AMS/5/77 (Giendarue l , Argy l l ) fi rst metaphase showing 72 bivalents ; D, AMS/9/77 (Glen Lochay, Mid Perth) diakinesis showing 7 2 bivalents ; E·F, AMS/2/77 (Lime H i l l , Sti r l i ng) diakinesis, both showing n = 72; G-H, 7/75 ( B ridgend, Banff) first metaphase, both showing n = 72 (all from permanent acetocarmine preparations , A·F x 800, G-H x 1 5 00) .

348 FERN GAZETT E : V O L U M E 1 1 PART 6 ( 1978)

cytotype are sign ificantly larger than those of known d ipl oid plants of A. cuneifolium (Re ichste in , pers. com m . ) . I n a pre l im inary i nvestigation (which w i l l be reported in ful l el sewhere ) , spore measurements were made using materia l from one Ir ish and ten Scottish local ities. lt was found that in these plants the spore s ize was larger than in central European materia l of A. cunei folium, but agreed closel y with that recorded for the Corsican tetraplo id. The pl ants from the B ritish I s l es thus correspond we l l with the newly-described tetraploid from Corsica in gross morphology, spore s ize and chromosome number. We bel ieve that these col l ections are identica l , and that they possi bly represent a tetraploid cytotype of A. cuneifolium Viv .

The question of the nature of th is tetrapl oid now arises. We consider it very l i ke ly that, as suggested by Deschatres, Schne l ler & Reichstein ( 1 978) , these plants are i ndeed the autotetraploid derivative of d ipl oid A. cuneifolium Viv . , but further work is necessary to confi rm th is hypothesis . Another poss ib i l ity is that Asplenium adiantum-nigrum, when growing on serpentine, can produce a certa in type of morphology which resembles A. cuneifolium . Th is, however, is u n l ike ly i n v iew of the fact that A. adiantum-nigrum and A. cunei folium grow together on · m ixed rocks wh ich conta in serpentine i n both Italy and southern Switzerl and. I n such pl aces not only can they be d istinguished morphologica l ly , but the triploid hybrid between them is known (A. x centovallense D. E. Meyer) (Meyer, 1 968) . A hybridi zation programme is at present in progress at Leeds, the aim of which is to e l ucidate the n ature and origins of material of tetraploid Asplenium cuneifolium from Corsica, Scotland and Ire land.

R E F ERENCES

D ESCHATRES, R . , SCHN ELLER, J .J . & R E I CHSTE I N , T. 1 978. A tetraploid cytotype of Asplenium cuneifolium Viv. in Corsica. Fern Gaz. 1 1: 343-44.

J ER M Y , A.C. , A R N O LD , H . R . , F A R R ELL, L. & P E R R I N G , F . H . ( Eds.) 1 978. A tlas of Ferns of the British Isles. London.

LOV E , A., LOVE, D .. & P I C H I SERMO L L I , R. E.G. 1977. Cytotf!xonomic A tlas of the Pteridophyta. Vaduz.

M EY ER , D. E. 1 968. Uber neue und seltene Asplen ien Europas. Ber. Deutsch. Bot. Ges. 8 1 : 92-1 06. ROB ERTS, R . H . & STI R LI NG, A. McG . 1 974. Asplenium cuneifolium Viv. in Scotland. Fern Gaz.

1 1 : 7-14. S H I VAS, M.G. 1 956. Some problems in cytology and taxonomy in the genera Polypodium and

Asplenium. Ph. D . thesis, Un iversity of Leeds. SHIVAS, M.G. 1 969. A cytotaxonomic study of the Asplenium adiantum-nigrum complex. Br.

Fern Gaz. 10: 68-80.

FERN GAZ. 11(6) 1978

THE PTERIDOPHYTES OF REUNION ISLAND*

F. BAD R E Museum National d'Histo i re Naturel le , Laborato ire de Phanerogamie,

16 Rue Buffon , Paris & Th. CADET

Domaine Un iversita i re du Chaudron, Laborato i re de B iologie Vegetale , lnstitut d 'Etudes Superieures Scientifiques, Ste . Cloti lde, l ie de la Reun ion

ABSTRACT

The pteridophytes of the is land of Reunion and their habitats are described.

INTRODUCTION

349

The pteridophyte f lora of Reunion Is land is character ized by a high num ber of species (about 240) in relation to its smal l surface area. This holds true for the entire Mascarene archipelago where the total number of species is known to be about 265, or about o ne-half the number occurring in Madagascar and the Seychel les.

One of the authors (T.C.) has been actively investigating the botany of Rt!un ion Island during the last ten years. His field o bservations, together with the results of many botan ical missions carried out by the other author ( F .B . ) and those of J . Bosser and F. Fr iedmann have permitted a general outl ine of the is land's present day pter idophyte vegetation to be establ ished . The col l ections are housed at the Paris Herbarium �nd/or at Centre Un iversita i re de La R�union.

In the past, ecological o bservations regarding the is land's pteridophytes have been rare; Cordemoy ( 1 895) , Baker ( 1 877) and Bory de Sai nt Vincent ( 1 804) usual ly give only vague ind ications consisting of the loca l ities without any mention of the biotope (habitat ) . The is l and's vegetation was studied by R ivals ( 1 952) but he scarcely mentions the pteridophytes.

Unti l the l ast few years the study of tropical f loras undertaken by large european i nstitutions has been a lmost exc lusively oriented towards a purely descriptive and systematic outlook.

Recently some ecological observations have been publ ished for Africa by Tard ieu-B iot, N ickles & Jacques- Fel ix ( 1 949), Tard ieu-B iot, Jaeger & Ad am ( 1 971 ) & Adams ( 1 954) . Concern ing the Mascarenes, most of the co l l ections were made by Bory de Saint-V incent, Boiv in , Commerson, Sieber, Gaud ichaud and Lepervanche-Meziere. These ancient collections are often very imprecise as to the local ity and the biotope (which a re generally not indicated ) , the col l ector merely stating "Mascarenes" or "Bourbon" (the island's previous name to 1 848) .

G EOGRAPHY AND R E LI EF OF T H E I SLAND

Reunion I sland, Maurit ius and Rodrigues form the Mascarene arch ipe lago . Reun ion (55° 30'E, 21 ° DO'S) l ies 800 km east of Madagascar. Maurit ius l ies closest to Reun ion at 1 70 km EN E . Rodrigues, on the other hand, is more isolated and is located 600 km EN E of Mauritius (f ig . 1 ) .

Reunion is or iented NW-SE and has a roughly el l i ptic contour, about 70 km long and 50 km wide, with a surface a rea of 2,500 km2. A geologica l ly young is land (about 3 mil l ion years old) of volcanic or ig in , it was formed from two volcan ic complexes, in the middle of which i s a vast expanse occupied by the Pla ine des Cafres and the Plaine • English trimslai:ion by D. Lorence, Mauritius Herbarium, M S I R I , Reduit, Mau ritius. (Present

address: Missouri Botanical Garden, 234!? Tower Grove Avenue, St. Louis No. 63 1 1 0, U.S.A.) .

350 F E R N GAZETTE: VOLU M E 11 PA RT 6 (1978)

30

4 0 !10 60 70

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20

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F I G U R E 1 . Position of the Mascarene Archipelago (Reunion Is land, Mau ritius, Rodrigues) in the I ndian Ocean, with respect to other island groups.

des Pal mistes ( F ig. 2 ) . The massi f du Piton des Neiges, representing the N E two-th irds of the is land, reaches 3,069 m. In the SE, the massif de la Fournaise has a crater wh ich i s sti l l active, r is ing to 2,630 m. Each of these two massifs is the resu lt of successive volcanic eruptions subsequently acted u pon by erosion. As a result, the topography is extremely rugged and is characterised by "ci rques" and rad iat ing va l leys with steep flanks bordering the rema ins of more or l ess extended expanses of somewhat regular slopes of about 1 0° incl i nation. The materia l detached by the sti l l active erosion has formed several. rather l imited l i ttoral pla ins extending from the mouths of some of the major rivers.

PHYSICAL AND C L IMATIC DATA

As a resu l t of its geographical situation, the is land enjoys a tropical c l imate with an insular character due to the inf luences of the trade wi nds and its accentuated relief wh ich modify an otherwise tru l y tropical c l imate. Two more or less wel l marked seasons exist. The warm and ra iny season (summer) lasts from December to Apri l . lt is marked by the passage of cyclonic disturbances over or near the is land wh ich bring very heavy rains. The cooler and rel atively drier season (winter) extends from M ay to November.

The temperatures are not excessive. Along the coast the mean maximum temperature for the warmest month· ( February) is 32.4°C at St. leu and 30. 2°C�-at St. Benoit. The mean m i n i mum temperature for the coldest month (August) is 1 S°C at St. ·leu and 1 6.4°C at St. Benolt. The temperature decreases with altitude ·and the h igher parts of the is land (above 1 800-2000m) are subject to frequent frosts at n ight. The temperature may reach -5°C at so i l level on the Massif de la F.ournaise .

·

BAD RE & CADET: PTERIDOPHVTES OF REUNION ISLAND 351

ALIZES 1LE DE LA

� REUNION

55"30 eat 10 km

FIGURE '2. Map of Rc:un1on Island show1n<1 ch"ef voican1c �1eas, drainage and preva1l11o<) 11\'lllti cii1 ection.

The mountain 1·ange results in mat·kedly different climates betwee11 tile windward and leeward reQions. The ESE: slopes, exposed to the direct fot-ce of the

t1 ade winds, experience a heavy rainfall (3m at St. Benolt) ancl have no ecolo�Jically

dry season (the pt·ecipitation is more thar1 110 mm at St. Benolt for each of the

months of A.ugust, September and October), In the leeward rai11-shaclovv of the

mountattlous sct·een, a rather marked dt·y season IJrevails frorn May to November and

the total yeariy 1 ainfall is much lovve;· (less than 800 mrn east of 1he f.JOrt of St. Louis).

In spite of t his, most of the island receives rnot·c than 1500 mm of rain yca;·ly, without

any ecologically dry pe1 iods. The reS)tons at low altitudes along the leeward zone are exceptional and the yea;·ly total is hequently less than 1 rn with a dry season that can

be rather marked.

352 FERN GAZETTE: VOLUME 1 1 PART 6 (1978)

V EG ETAT I ON

As one goes from low to high altitude, the general aspect of the plant communities varies following more or less horizontal bands. This altitudinal succession of stages of vegetation depends on various factors among which are the decrease in temperature with altitude and the situation in relation to the ESE trade winds. The main zones of vegetation are as follows:

Littoral Vegetation

The original littoral vegetation has totally disappeared and has be'en replaced by secondary formations composed of numerous exotics with a few rare indigenous halophiles (Scaevola taccada (Gaertn.) Roxb., Lysimachia mauritiana Kam. and Zoysia tenuifolia Willd. ex Thiele).

Marsh Vegetation

Behind the littoral strands along certain coastal areas (St. Andre, St. Paul, Le Gol), marshes have developed which are flooded periodically. These have been colonized by large heliophytes among which the Cyperaceae are prevalent (Cyperus papyrus L. var. madagascariensis (Willd.) Kunth, C. articulatus L., ·Eieocharis equisetina Presl. and Typha angustifolia L. )

Megathermic Dry Sector Vegetation

This formerly occupied the zone occuring between the littoral and altitudes of 600 -700 m in the leeward regions. Degraded remnants of this vegetation still exist along the vertical walls enclosing some of the large rivers (Riviere de St. Denis, Ravine de la Grande Chaloupe, Riyiere des Galets, Bras de Cilaos and Bras de la Plaine). Species characteristic of this vegetation type may often be encountered in the form of a few isolated individuals� Some examples are : Foetidia mauritiana Lam., Erythroxylum hypericifolium Lam., Olea chrysophylla Lam., and Cossignia pinnata Lam. This formation probably occupied, at least in part, what today consists of lowland savanna of Heteropogon contortus Beauv. ex Roem. & Schult. and Bothrioch/oa pertusa (L.) Camus which have developed from the Massif de la Montagne (between 0 and 300 m) to the Plaine du Gol (near sea level at St. Louis).

Low Altitude Hygrothermic Forest or Lowland "Bois de Couleur" Forest

This formation formerly covered the lower slopes of the eastern region between 0 -800 m, and in addition a narrow band in the west above the megathermic dry sector vegetation, between 700 and 1 000- 1 1 OOm. Today only more or less degracjed vestiges remain at the Massif de la Montagne, the Plaine des Makes and above 600 m in the windward region. Some few remnants may also be seen in the region of St. Philippe and Grand Brule below 400 m.

This type of vegetation consists of three characteristic strata : arborescent (average height of 1 0 - 1 5 m), understory shrubs, and herbs with the presence of numerous epiphytes (ferns and orchids). The most characteristic species are : Sideroxylon majus (Gaertn. f.) Baehni, Mimusops maxima (Lam.) Vaughan, Labourdonnaisia cal/ophylloides Bojer, Mal/otus integrifolius Mull. Arg., Ca/ophyllum inophyl/um L., Hyophorbe indica Gaertn., Ochrosia borbonica Gmel., Eugenia cymosa, Lam., Eugenia paniculata Lam., and Diospyros melanida Poir.

BADRE & CADET: PTER I DOPHYTES OF R EU N I ON I SLAND 353

F I G U R E 3. Nephrolepis abrupta, the first vascular plant on 1 96 1 lava flow covered with the l ichen Stereocaulon vulcani. Grand Brule , 1 00 m.

High Altitude Hygrophylic Formations

These formations represent the best preserved stands of primary vegetation in Reun ion today . The lower l i m i ts rise progressively from 700-800 m in the southeast and east to 1000 = 1100 m in the West and the uppe� l imits extend from 1500- 1600 m to about 2000 m. The floristic composition and physiognomy can be su bd ivided as fo l lows:

1) The hygroph i l ic Dombeya or "Bois de cou leur des Hauts" forest. I n th i s type of forest the canopy trees rare ly exceed ten metres. Epiphytes abound from ground l evel to the highest branches (e.g . at Pl ateau de Bebour and P la i ne des Chicots ) . The most characteristic woody species are : Dombeya reclinata Cordem., D. punctata Cav., Eugenia cotinifolia Jacq ., Bertiera rufa A. R ich and Cladoxylon glandulosun Bail I .

2)' The "Tamar in des hauts" forest (Acacia heterophylla ( Lam. ) W i l l d . ) . In the west at about 1300-1400 m the Dombeya forest passes progressively into a formation where Acacia heterophylla and Nastus borbonicus Gmel . are dominant. The latter species, a bamboo, forms an extremely dense but di scontinuous lower stratum at P la ine des Ch icots for exampl e. The Nastus borbonicus stratum is inex istent on the east of Massif du Piton des Neiges (North of P la i nes des Cafres, Bebour and Bel ouve ) . Here i t is repl aced either by ericoid shru bs (Phllippia, Senecio, Stoebe a n d Phylica) or by species found in the Dombeya forest.

3) Hygroph i lous thickets of Pandanus montanus Bory. This formation type occurs on the eastern and northern slopes of the Massif de la Fourna ise in a region receiv ing 5-6 m of ra in yearly. Numerous tree ferns (Cyathea spp . ) and Acanthophoenix pa l ms impart a characteristic physiognomy to this formation .

High Altitude Ericoid Vegetation

This formation begins at 1600-1700 m in the windward and at 2000 m in the leeward

F I G U R E 4. A group of Dicranopteris linearis (broad frond) and Sticherus falgellaris (narrow frond) in a pioneer shrubby vegetation along the road from St-Benoit to Plaine des Palmistes,

700 m.

FIGURE 5. A typical thermophi l ic and ski o­ph i lous species, the epiphytic fern Antrophyum giganteum. La Mare Longue forest near St-

P h il ippe, 300 m.

FIGURE 6. Another typical fern species of the hygrophi lous and thermoph i l ic forest, the epiphytic Asplenium nidus with very large fronds

attaining 2 m .

w t11 �

., fT1 ;o z " )::> N fT1 .., .., fT1 < 0 r c s fT1 .... .... 1l )::> ;o .., "' .... "' " "'

BAD R E & CADET: PTE R I DOPHYTES OF R E U N I O N I SLAND 355

regio n . it consists of more or less dens!! thickets of ericoid shru bs (Philippia montana (Wi l l d . ) Klotzsch, Stoebe passerinoides ( Lam. ) Wi l ld . , Senecio hubertia Pers. and Phy/ica leucocepha/a (Bory ) Cordem.) and a lso herbaceous or bushy montane species (Faujasia pinifolia (Bory) Cass., Eriothrix lycopodioides ( Lam.) D .C. , Psiadia spp. and Heterochaenia rivalsii Badre & Cadet) .

Although the predominance o f Philippia montana imparts a u n iform appearance to this formation, variations in c l imatic and edaph ic factors resu lt in a number of subgroups; two of these a re as fol lows:

1) Along its lower l i m its and in windward areas of very h igh ra infa l l the ericoid vegetation forms a very dense heath scru b of Philippia sheltering a herbaceous stratum rich in ferns. Beneath this primary vegetation , loca l ly ca l l ed "vou ne" or "avoune", there exists a thick cush ion of raw humus which may exceed one metre i n depth .

2) High mounta in pra iries. These are edaphic in orig in , and deve lop over fine so i l and debris which has accumulated in depress ions. These pra ir ies are rich in composites, Cyperaceae and Graminae (e .g. Helichrysum arnieoides ( Lam. ) Cordem., Psiadia aspera (Bory ) Cordem., Festuca borbonica Spreng. ) and a lso h arbour two lycopods : Lycopodiella affinis (Bory ) P ich.Serm. and Huperzia saururus ( Lam. ) Roth m .

· · ·

D E F I N I T I O N OF T H E P R I NCIPAL ECOLOGICAL GROUPS

The d istr ibution of pteridophytes on the isl and accord ing to geography and station appears to depend upon three principal factors : temperature, l ight and humid ity. The latter factor is the least decis ive because of the h igh ra infa l l that most of the is land receives.

The is land 's pteridophytes can be d iv ided into two principal groups: those of forest formations including the pioneers (p ioneer vegetation of Nephrolepis abrupta (Bory) St. John, pre-forest Sideroxylon association and Philippia scru b) ; and those which are associated with marsh vegetation , savanna, abandoned fields or have a more or less ruderal character.

Amongst the forest species, variat ion in temperature with al titude enable three categories of species to be defined: • Thermoph i l ic species of low to medium altitudes, 0 to 700-800 m , but extending to 1000- 1 100 m in the leeward zone , or even to 1200- 1300 m in the cirque de Mafate ·a nd drque d e Ci laos where the alt itude-temperature gradient d iffers from the usual one. • Ol igothermoph i l ic species of extremely hygroph i l ic h igh a l titude forests and ericoid vegetation of upper regions above 1000-1 100 m. • Eurythermoph i l ic species occu rring with the same frequency from sea level to the h ighest a l titudes. With in the l i m its of the is land, these species appear to be i nd ifferent to temperature.

In each of the above three categories the l ight factor enables a further breakdown into: • Hel ioph i l ic to hemi-skioph i lous species. These are species of pioneer shrub formations, secondary scrubs occupying old abandoned f ie lds or of forest clearings. • Skioph i lous terrestrial species growing beneath dense forests. • Skioph i lous epiphytes.

A group of species apparently restricted to remnants of forest i n the warmer and dr ier regions of the west (the dry megathermic sector of R I VA LS, 1952) is

FIGURE 7. 8/echnum tabu/are, anol igothermic and pioneer species of fern with a cycad-1 ike habit. Philippia thicket on recent lava f low at Basse

Val lee, St·Ph i l ippe, 900 m.

F IGURE 8. Vittaria isoetifo/ia , with its long and very narrow fronds in tuft on the lower face of bowed trunks. Hygroph i lous forest of Bebour,

1 350 m .

F I G URE 9 . The very commun Antrophyum boryanum, an epiphytic, l ithophytic or even

terrestrial fern . Bebour, forest, 1 350 m.

w (11 Ol

"T1 ITl ::0 z G) )> N ITl -i -i ITl < 0 r c s: ITl ... ... "0 )> :c -i "' ... lO ..... �

BAD RE & CADET: PT E R I DOPHYTES OF REUN ION ISLAND 357

characterized equal ly by numerous ·species of phanerogams which , l i ke certain pteridophytes, are no longer to be found on the is land (thermoph i l i c and more or less xeroph i l i c species) .

Amongst the non-forest species which are for the most part thermoph i l ic hel iophi les, there are : • Saxicol ic, more or less xeroph i l ic species. • Hygroph i l ic species of marshes, edges of water courses and seepage . • Terrestr ial species, some of which are more or less ruderal .

FOR EST F E R N SPECI ES

These constitute the majority of the is land 's pteridophyte flora including more than 80% of the species.

Thermophilic forest species

The thermoph i l ic species are associated with forests at the lower stage of vegetation occupy ing certa in of the lower s lopes of the island between 0 and 700-800 m altitude on the windward and 1 000-1 1 00 m on the leeward aspects.

These species are a l l more or l ess hygrophyl ic. More precisely, the humidity is qu ite sufficient here to assure thei r optimal deve lopment as a whole without much variation into su b-categories, except for those species of the "dry megathermic sector" as defined above .

Heliophilous or hemi-skiophilous species

These are essentia l ly pioneer species coloniz ing l ava flows . Some of these also occur in abandoned fields, others prefer forest clearings. Nephrolepis abrupta ( Bory ) Mett. , Sticherus flagellaris (Bory ) St. John, and Dicranopteris linearis (Burm . f. ) Underwood are the three species wh ich co lonize recent volcanic flows ( l ess than a century old) before the shrubs and trees have created a continuous canopy , at Grand Brule , for example. The latter two species are also encountered in cons iderable a bundance in more or l ess degraded formations on mounta in crests in a l l the low, humid regions of the is land, particularly in the East ( Hauts de St. Benolt and of St. Andre ) .

Sphaerostephanos elatus (Boj . ) Holtt. (Cyclosorus mauritianus ( Fee) Tard. ) is a large, relatively hygroph i l ic fern very common in clearings, often along forest paths and roads, where i t forms dense colon ies. Ochropteris pal/ens (Sw.) J. Sm . , Lindsaea ensifolia Sw. (Schizoloma ensifo/ium (Sw . ) J . Sm . ) , and Sphaerostephanos arbuscu/a (Wi l l d . ) Holtt. (Cyclosorus arbusculus (Wi l ld . ) Ch ing ) , are less frequent, and the l atter often grows in semi-shade, occupying rock fissures in stream beds . Sph,enomeris chinensis (L.) Maxon is most frequently encountered in shrub formations occupy i ng abandoned fields or a long forest borders, paths and roads.

Skiophilous terrestrial species

The species i n this category are not very nu merous. The authors can cite Angiopteris madagascariensis De Vriese wh ich had never before been recorded from Reun ion, and is known only from the forest of Brule de Takamaka in the southeast. Also belonging to this .grou p are species of Ctenitis (Nos. 3572 and 437 1 ), Selaginella obtusa (Beauv . ) Spri ng, of wh ich there exists a form (or var iety?) restricted to the rocky l ittoral of the southeast, and Selaginella falcata (Beauv. ) Spring, which ranges up to 1 1 00- 1 200 m altitude.

358 FERN GAZETTE : V O L U M E 11 PART 6 ( 1978 )

FIGURE 10. Elaphoglossum sp/endens, a typical epiphytic and skiophi lous fern of the high altitude forest growing with the fi lmy fern Hymenophyl/um inaequa/e on an horizontal trunk.

Bebour forest, 1 350 m. ·

Skiophilous epiphytic species

Certa in of these can develop on rocks, at the bases of large tree trun ks or on a su bstrate of st i l l intact l ava and constitute an essential part of the berbaceous stratum, but disappear where there i s a true soi l . Such i s the case with Nephrolepis biserrata (Sw.) Schott and Phymatodes scolopendria (Burm. f . ) Ch ing, both very abundant i n forests occupying modern volcanic flows ( 1 00·20Q years) in the southeast (St . Ph i l i ppe region ) .

The true epiphytes i n th is group are numerous, certai n of them are frequent and abundant: Hymenophyllum sibthorpioides (Bory ex Wil ld . ) Mett . ex Kuhn , Hymenophyl!um hirsutum ( L . ) Sw., Trichomanes bipunctatum Pair., Trichomanes giganteum B ory, Ophioglossum pendulum l., Humata repens ( L.f.) D iels, Vittaria ensiform is Sw., Asplenium pellucidum Lam . (3404, 3388, 3595) , Asplenium nidus L, (with immense fronds atta i n ing 2m), Microsorium punctatum (L.) Cope!, Belvisia spicata (l.f.) Mirb., Arthropteris boutoniana ( Hook . ) Pich . Serm . , a nd A. giganteum Bory (fi g. 5).

The remain ing spec ies are not particu l arly rare, but are represented by fewer ind ividuals: Antrophyum immersum ( Bory ex Wi l ld . ) Mett., Elaphoglossum lepervanchei ( F�e) Moore, Lomariopsis pol/icina (W i l lem. ) Mett. ex Kuh n ., Vittaria scolopendrina ( Bory ) Thwait., Vittaria elongata Sw., Xiphopteris serrulata (Sw.) Kaulf., Trichoman.es bonapartei C. Chr. (Cadet 3333 and 3764) .

Forest species within the dry megathermic sector

These tend to be more or less xeroph i l ic . They can susta in a dry period sometimes exceeding two months (August·September ) . Their l eaves are able to remain in a shrivel led state or tolerate the dryness because of the i r coriaceous lamina .

B A D R E & CADET: PTER I DOPHYTES O F R E U N I O N I SLAN D 359

The more characteristic terrestrtal species are: Schizaea dichotoma Sm. , Tectaria puberula ( Desv . ) C . Chr. (37 1 1 and 4 1 1 7) , Asplenium adiantoides ( L .) C . Chr., Asplenium viviparum ( L . F . ) Pres l . , Asplenium pellucidum Lam. var. dareaefolium (Bory) Tard . , Adiantum reniforme L. var. asarifo/ium (Wi l ld . ) S im, and Adiantum hispidulum Sw. The latter two species have never been observed by the authors on the more humid side of the is land (with the exception of a s ingle station for Adiantum hispidulum) and apparently cannot tolerate a h igh and constant humid ity .

Epiphytes are rare in this group. Arthropteris orientalis (J . F . Gme l . ) Posth . thrives at the base of trunks and on rocks in open understories. l t can also tolerate exposu re to ful l sun and i ts fronds shrivel completely during the dry season. Trichomanes pyxidiferum L. var . melanotrichum (Sch lechttend.) Sche lpe is of rare occurrence. The commonest epiphytes are in fact those species with a l arge ecological ampl itude for water. Abundant principal l y i n the humid region, they persist equal ly in the dry sector, but develop less copiously .Th is is the case with Nephrolepis biserrata (Sw . ) Schott and Phymatodes scolopendria (Burm. f . ) Ch ing.

Oligothermic forest species

These may be encountered beg inn ing at 800-900 m alt itude i n the east and about 1 000 m in the west. Strongly hygrophi l ic, they are restricted to humid Dombeya forests and erico id vegetation of h igh alt itudes.

He/iophilic to hemi-skiophilous species

Certa in of these demand a fair ly h igh l i ght intens ity and grow in rather open tree formations a long forest borders, ravi nes and roads, or in natural clearings. 8/echnum tabu/are (Thunb. ) Kuhn, a l arge fern with a cycad-l i ke habit, prefers Philippia th ickets over intact l ava flows for its habitat and occurs principa l ly on the M assif de l a Fournaise around the active volcano. Bory d e Saint-Vincent named the Pla ine des Osmondes after this im pressive fern . 8/echnum montbrisonis C. Chr . has more or less the same biotope and abounds beneath Philippia thickets covering intact l ava flows between about 1 500-2000 m altitude . Th is species a l so commonly grows inside rav ines in dense rain forests. Certa in other species are restricted to clearings, particu larly in the 'Tamarin des Hauts" forests: Hypo(epis villoso-viscida (Thouars) Tard . , Histiopteris /ncisa (Thunb.) J . Smith, Athyrium scandicinum (W i l ld . ) C . Pres l , fseudophegopteris aubertii (Desv . ) Holtt. (Thelypteris cruci<Jta (Wi l l d . ) Tard . ) , Ophioglossum ovatum Bory and 0. reticu/atum L. may even grow in clear ings with in Casuarina, Eucalyptus or Acacia plimtation _s_

The remain ing species tend to occupy the l ower stratum of pioneer ericoid formations: Lycopodium clavatum L. var. borbonicum Bory, Mohria caffrorum ( L . ) Desv., Gleichenia boryi Kze., Amauropelta sa/azica (Holtt.) Holtt., Huperzia saururus ( Lam . ) Rothm., Lycopodiella affinis (Bory ) P ich i Sermol l i . The l atter two species are characteristic of high mou nta in prair ies. Huperzia se/ago ( L.) Bern h. ex Schran k & Mart. is known only from a s ingle station at Petit Matarum i n the Cirque de C i l aos. Cyathea g/auca Bory is a component of the u pper stratum in pre-forest formations and imparts a characteristic physiognomy to these.

Skiophilous terrestrial, more or less humilo/ous species

There are many species which are constant and h ighly characteristic com ponents of the ground flora of high alt itude rain forest : 8/otie//a pubescens (Kau lf. ) Tryon, Athyrium arborescens (Bory ) M i lde, Po/ystichum ammifolium (Po i r . ) C. Chr .,

FIGUR ES 1 1 and 1 2. The obligothermic tree fern Cyathea glauca. Hygrophilous forest on the ridge between C irque de Mafate and Cirque de Salazie, 1 600 m .

FIG U R E 1 3: A n eurythermic terrestrial and skiophilous fern : Marattia fraxinea. La Mare

Longue forest near SH'hi l ippe 300 m.

w Ol 0

., [11 :0 z

C) l> N [11 -i -i [11

< 0 r c s: [11 ... ... "lJ l> :0 -i "' ... \0 ..... "'

. . BAD R E & CADET : PTE R I DO PHYTES O F R E U N I O N I SLAND 36 1

Amauropelta heteroptera (Desv. ) H.oltt. (Thelypteris heteroptera (Desv . ) Tard . ) , Amaurolpelta strigosa (Wi l l d . ) Holtt. (Thelypteris tomentosa (Thouars) Ching) , Dryopteris aquilinoides ( Desv. ) C. Ch_r ., Ctenitis subglandulosa ( M.ett . ) Tard., Ctenitis crinita (Poi r . ) Tard., Ctenitis mascarhenarum - Januginosa group, and Ctenitis sp. (Cadet 4 1 54 a nd 4360 ) . Other less abundant species i nclude : Selaginel!a cataphracta (Wi l ld . ) Spring, Ctenitis sp. (Cadet 4 1 55) a nd Pteris croesus Bory .

I n the l atter category w e can a lso i nc lude Asplenium unilaterale Lam ., an extremely hygroph i l ic species which thrives on humid soi l and i s particu l arly fond of humid rocks i n shady stream beds and Pityrogramma argentea (Wi l ld . ) Dom i n . which favors o ld fa l len trun ks or humus tussocks especia l ly in o ld Acacia heterophyl/a forests.

Skiophilous epiphytes

These species occur on tree trunks at various levels but a lways in the shade of the canopy . Certa in of them are particu l arly common : Pleopeltis excavata (Bory ex Wi l ld . ) Schelpe, Vittaria isoetifolia Bory (with long and narrow pendant fronds ) , Asplenium aethiopicum (Burm.f. ) Bech. (Cadet 3 1 87, 351 2 and 4 1 1 4) , Asplenium boltonii Hook . ex Schelpe, Elaphoglossum aubertii (Desv . ) Tard . , Elaphoglossum splendens ( Bory ex Wi l ld . ) Brack . , and Elaphoglossum hybridum (Bory ) Brack . Others are less common and i nclude : Huperzia verticil/ata ( L .f .) Rothm. , Huperzia obtusifolia (Sw.)

. Rothm., Hymenophyllum peltatum Desv., Asplenium protensum Schrad . ,

Asplenium rutifolium ( Berg.) Kze., Asplenium theciferum ( Ku nth ) Mett. , Ctenopteris leucosora (Boj . ) Tard., and Ctenopteris parvula ( Bory ex Wi l ld . ) J . Smith.

Some species, although consistently found growing on the lower and middle leve ls of trun ks, tolerate increased l ight and may a lso become establ ished on h igh and exposed branches. They may even be encountered with i n dense Philippia th ickets at bases of shru bs or rooting in carpets of moss . They include the fo l l owing species : Blotiel/a glabra (Bory ) Tryon, Elaphoglossum angulatum (8 1 . ) Moore (E. alstonii Tard . ) , Elaphoglossum sp :, Ctenopteris rig{Jscens (Bory ex W i l ld .) J . Sm ., Ctenopteris torulosa (Bak. ) Tard ., , Pleopeltis macrocarpa (Bory ex Wi l ld . ) . The l atter species is particu larly abundant on the trun ks and branches of Acacia heterophy/la .

Cavernicolous species

A certai n number of species favour rocky wal ls of grottos, f issures i n c l i ffs, or rock concavities at h igh a ltitudes. These incl u de : Asplenium kassneri Hieron . , Asplenium �rectum Bory ex W i l ld ., Asplenfum stoloniferum �ory, Cystopteris fragills ( L. ) Bernh. , Ctenitis sp. ( 1 942, 1 974, 2047, 1 532, 1 553), Elaphoglossum deckenii ( Kuhn) C. Chr. var.rufidulum (Wi l ld . ) Tard., Elaphoglossum hybridum (Bory) B rack.v1Jr. vulcanii Lepervanche ex Fee, and Elaphoglossum stipitatum (Bory ex Fee) Moore. Grammitis barbatula ( Bak . ) Cope ! . is consistently found in this biotope, but may a lso occur i n forests i n extremely sheltered sites, e .g. on the lower surface o f inc l i ned trun ks. Cheilanthes farinosa (Forsk . ) Kaulf. is more or less hel ioph i l ic and occurs at the mouths of caverns or on the edges of c l i ffs.

Eurythermic forest species

In view of their geographic distribution over the is land, these species have a wide tolerance for temperature. They are just as common i n forests of low al titude as they are in those of the uplands. .

I n terms of biomass they are without equal amongst the pteridophyte flora.

362 F ERN GAZETTE : V O L U M E 1 1 PART 6 ( 1 9 78)

The tree ferns

The tree ferns have a special appearance wh ich i mparts a characterised physiognomy to much of the is l and 's forested expanses, so we shal l give it speci al consideration . Two of the component species a re tru ly polyaltitudi na l . The fi rst, CVathea borbonica Desv. (C. canaliculata W i l l d . ) , has a fai rly sl ender stem wh ich often becomes ramif ied at h igher alt itudes. l t is general ly a component of the canopy where the trees exceed 7-8 m . Cyathea excelsa Sw. is , on t h e other hand, a l arge tree fern attai n i ng 1 0· 1 2 m . I ts fronds are a component of and often transcend the canopy. The base, which is thickened by a dense network of adventitious roots, is used for the construction of planters ( "fanjans ') or support plaques we l l su ited for orch id cu lture .

Cyathea glauca Bory i s much more o l igothermic and is never found below 1 000-1 1 00 m alt itude. A pioneer species in ericoid formations, it dominates the upper stratum of preforest shru b vegetation for qu ite some time. Dur ing the hot and humid period i t s leaves dry up , after which new growth i s i n iti ated. The base of the stem of this species is used in the same way as that of Cyathea excel sa .

A fou rth species of Cyathea , probably introduced , is cu ltivated in humid regions of low alt itudes (Ste. Rose, St. B enoit, Plaine des Pa l m i stes) , where it now appears to be natu ral ized .

Heliophilic species

These species are not very numerous and three can be cited . Lycopodie/la cemua ( l . ) Pich . Serm . i s common with i n pioneer shrub formations and als_o_ in fa l low land, particu lar ly those of very humid regions . Pteridium aquilinum ( L. ) K uhn i s a lmost ubiqu itous in f ie lds on poor soi l , fa l l o w land, grave l ly areas, secondary scrub and even more or less degraded forests. This incredib le fern sometimes exceeds fou r metres i n height. Elaphoglossum spatulatum (Bory ) Moore is a t iny fern which grows exc l l.Hiively on exposed and humid boulders in sh1; ltered streambed . This species cou ld be considered to be a he l ioph i l i c saxicole.

Skiophi/ous terrestrial species

At ti mes these constitute the greater part of the forest ground flora. Examples include : Selaginella sinuosa (Desv . ) Alston , Selaginella surculosa Spring, Marattia fraxinea Sm, ex J. F . G mel . , Pteris scabra Bory ex W i l ld . , A splenium viviparum ( l.f. ) Pr. var. lineatum ( Sw. ) Tard. and Ctenitis sp. (Cadet 1 674 3399, 3472, 3378, 3544, 3555). The rema in ing species are much less frequent : Trichomanes meifolium Bory , Trichomanes parviflorum Pair . , Nephrolepis tuberosa Bory, Pteris cretica L. , Pteris woodwardioides Bory ex Wi l ld ., and 8/echnum australe L.

Eurythermic, skiophilous epiphytes

Most species of th i s group are genera l ly qu ite frequent. Certain are strict skioph i le : Huperzia squarrosa (G. Forst.) Trev., Huperzia gnidioides ( L.f. ) R othm., Huperzia ophioglossoides ( Lam. ) Roth m ., Asplenium petiolu/atum Mett., Hymenophyllum hygrometricum Desv.. Hymenophyllum inaequale Desv ., and Hymenophyllum capillare Desv. which is very exacting as far as shade is concerned, and is a lways found on the l ower su rfaces of i ncl i ned trunks or at base of trees.

Trichomanes erosum Wi l ld . (probably synonymous with T. cuspidatum W i l l d . ) is also extremely hygroph i l ic and has the same habitat as the preced ing species but a lso grows c loser to or even on the soi l . The tiny fronds shrivel readi ly with the s l ightest decrease in hum id ity. Trichomanes tamarisciforme Pair and Elaphoglossum

B A D R E & CADET: PTER I DOPHYTES O F R EU N ION ISLAND 363

tomentosum (Bory ex Wi l ld ) Christ are a lso present. Antrophyum boryanum (Wi l ld ) Kaulf. is often l i thophytic or even terrestr ia l . Blechnum attenuatum (Sw.) Mett. occasional ly forms a complete col lar around trunks, especia l ly those of Cyathea. At middle a ltitudes the species may acqu i re a terrestrial habitat and even constitute a dominant part of the herbaceous stratum . Loxogramma lanceolata (Sw.) C . Pres l . quite often l i th ophytic, can withstand short periods of dessication . l t a lso occurs i n the Eastern dry zone i nside ravi nes.

Certa i n other species are encounted less frequently : Psilotum nudum ( L . ) Beauv. ( i n crevices of more or less shaded rocks ) , Trichomanes borbonicum Bory, Trichomanes digitatum Sw., Cheiroglossa malagassica (C. Chr. ) Pich. Serm . (C. palmata Presl var. madagascariensis C. Chr. ) , Elaphoglossum richardii (Bory) Christ, and Monogramma graminea (Poir.) Schkuhr.

Although indeed very abundant on trunks i n the shade, another group of species is equal ly at home on high branches exposed to fu l l su n . These include : Rumohra adiantiformis ( Forst. ) Ching, Oleandra distenta Kunze, Elaphoglossum macropodium ( Fee) Moore, Elaphoglossum petiolatum (Sw.) U rban ssp. salicifolium (Wi l l d . ex Kau lf . ) Schelpe, Ctenopteris argyrata (Bory) Tard ., and Grammitis obtusa W i l l d .

N ON FOR EST F E R N SPE C I ES

The pteridophyte flora outside of the forest is poorly represented, probably because the biotopes are not very d iverse. A l l thermoph i l ic, these species can be d iv ided into three ecologic categories.

Saxicolious, he/iophilous more or less xerophilic species

Not very numerous, these species are h i gh ly characteristic of the "dry megatherm ic sector". They l ive i n small cracks and fissures of the most exposed rocks and the i r fronds dehydrate completely dur ing the dry season. Actiniopteris austral is ( L . f . ) L ink and Actiniopteris radiata (Sw.) L. are characteristic. The l atter species can a l so be found between rocks of wal l s a long roads. Adiantum rhizophorum Sw. prefers a more protected habitat and retains its leaves year round . We can add to this group Pyrrosia lanceolata ( L . ) Farw. which is fou nd equa l ly i n the very humid eastern zone. l t grows on isolated tree trun ks and can withstand fair ly prolonged dessication during the dry seaso n .

Terrestrial, heliophilous, more o r less ruderal species

A number of species have an ecology sometimes difficu lt to define . They commonly occur a long roads, i n f ie lds at the base of dry stone wal ls, i n gravel and sometimes in fa l l ow land.

Pl ants of such situations include : Pellaea viridis (Forsk.) Prant . var. viridis and Asplenium adiantum-nigrum L. Equisetum ramosissimum Desf. i s a l most a lways encountered on the mo ist a l l uv ium deposited in torrent beds or on their ban ks but a l so occurs on impermeable soi l with i n the "cirques", where it atta ins 1600- 1700 m altitude. Ophioglossum lancifolium C. Pres l and 0. nudicaule L.f. are d imi nutive ferns a l l ied encountered in Heteropogon sava nnahs in the west. Their fronds appear just after the fi rst ra ins mark i ng the end of the dry season . Th is spec ies has the same ecology in Madagascar. Pteris linearis Pa ir . occurs at the foot of wal l s in the dry western region . Pityrogramma calomelanos ( L. ) L ink . va r . calomelanos grows between rocks i n stream beds that are a lmost always dry and a lso a long roadsi des. Pityrogramma calemelanos var. aureoflava (Hook.) Weath . ex . Bai ley i s commonly

364 FERN GAZETT E : V O L U M E 11 PART 6 ( 1 9 7 8 )

situated along road sides. Sphaerostephanos unitus ( L ) Holtt . (Cyclosorus unitus ( L .) Ching) is extremely frequent in abandoned fields and along roads. Macrothe/ypteris torresiana (Gaud. ) Ching (Thelypteris uliginosa (Kunze) Ching) may occur between rocks of torrent beds which a re for the most part dry .

Certai n species are extremely local ized , being restricted to one or two "ci rques". Cheilanthes hirta Sw. , Pellaea calomelanos (Sw.) Link . var . calomelanos and Pellaea dura (W i l l d .) Hook. are known only from the Cirque de Ci laos and Ci rque de Mafate. Two other species are known exclusively from the Ci rque de Ci laos : Doryopteris pedatoides ( Desv . ) Kuhn. and Doryopteris pi/osa (Po i r .) Kuh n . Al l of tl:lese species are absent from the C i rque de Salazie, which is much more humid . They can be considered as species wh ich are thermoph i l ic but scarcely hygroph i l ic .

Hygrophilic and he/iophilic species of marshes, water courses and seepage

Not many species grow in this biotope . Cyclosorus interruptus (Wi l l d .) H . lto (The/ypteris totta (Thunb. ) Schelpe) i s abundant around marshes at low to medium alti tudes. Osmunda regalis L . grows i n areas of marshy prair ie below the v i l l age of Plaine des Palmistes, the only known stat ion . Athyrium accedens (8 1 . ) M i lde (Diplazium proliferum ( Lam .) Kaulf . ) and Pteris pseudolonchitis Bory are most frequently encountered amongst rocks a l ong permanent streams or springs, or on talus slopes a long i rr igation canals at low al titudes.

The flora of waterfal l s and seepage at low alt itudes is characterised by Adiantum capi/lui-veneris L., and Ptefis vittata L. the latter of wh ich is not exclusively found in this habitat and occasionaly occu rs a long streams on humid al luvia ls . Christe/la hilsenbergii (Presl) Holtt . i s a sun lov ing species which is not very particular in its water requirements. lt is also found on seepage areas as wel l as on the al most permanently dry s i.l ty banks of streams and in the u ndergrowth of forests of the hot dry parts of the is land.

CONCLUS I O N S

Most of the 240 or so species of native pteridophytes are sti l l abundant i n Reun ion because they occupy habitats which are presently qu i te extensive and they do not have ecological requirements that are h ighly exacting. Many hygroskiophi lous species of low alt itudes, for example, may thr ive in secondary formations (Eugenia jambos L . forests) wh ich have taken the pl ace of the indigenous forests. Other species, notably those belonging to the genera Hymenophyllum, Trichomanes and Humata, even grow on o ld fru it trees in orchards. On the other hand, as a consequence of the reduction of the areas once occupied by the forests in the dry megathermic sector, certain species restricted to this formation have become rare, tor example Asplenium adiantoides ( L.) C. Chr. , Actiniopteris radiata (Sw. ) Link , and especia l ly Actiniopteris australis ( L.f . ) L ink wh ich i s confined to emergent rock faces in the Heteropogon savanna of the leeward region . These species .an� i nfrequent and m-ore importantly, are me�aced by fires. Pel/aea ca/omelanos ( L. ) L ink var. calomelanos, Ooryopteris pedatoides (Desv.) Kuhn, and D. pi/osa (Poir) Kuhn are only encountered at rare stations, pr incipal ly in the C i rque de C i laos, in areas alternatively cultivated and left fallow. Asplenium nidus L. is also in danger because it is often col lected for its attractive fronds.

Various other species such as Vittaria sco/opendrina (Bory) Thwait. and Angiopteris madagascariensis De Vriese are l imited to areas of low a ltitude humid forest which have become establ ished on l ava flows about 200 years o ld . The i r restricted distr ibution can only be explained by man's destruction of this type of

BAD RE & CADET: PTE R I DOPHYTES O F R E U N I O N I S LAND 365

format ion _ These species a re thu s threatened by exti nction .

ACKNOW L E DG EM ENTS

We wish to thank M r . D . Lorence who k ind ly accepted to transl ate this paper from

French to Engl i sh and Dr. Page who further prepared the text .

B I B LIOGRAPHY O F MASCASCAR EN E PTER I DO LOG Y

ADAMS, C . D . , 1 954. The a ltitudinal distribution of West African Pteridophyta Rapp_ Comm. 8eme Congr. ln t. Bot Paris, sect. 7-8 : 1 79-1 84.

BAK E R , J .G . , 1 877. Flora o f Mauritius a n d the Seychelles. London . BOJ ER W ., 1 837. Hortus Mauritianus. Maurice BORY DE SAI NT-V I NCENT, 1 804. Voyages dans les Qua tres Principales lies des Mers d'A frique

. . . . 1, 2, 3. Paris . CH R I ST E N SEN, C. 1 932. The Pteridophyta of Madagascar. Dansk. Bot. A rk. 7: 1 -253. CO R D EM O Y , E.J. de, 1 895. Flare de l'ile de la Reunion. Paris. HO L TTUM, R . E. , 1 954. Flora of Malaya, Ferns. Singapore. H O LTTUM, R . E . , 1 974. Thelypter idaceae of Africa and adjacent is lands. Journ. S. A fr. Bot. 40

(2) : 1. 23-1 68. R I V A LS, P. , 1 952. Etudes sur la vegetation nature l le de l ' i le de la Reunion . Tra v. Lab. Forestier

Toulouse 5 ( 1 ) , 2 1 4 p. SCH E LP E , E . , 1 956. Distributional ecological and phytogeographical observations on the ferns of

south-west Africa. Journ S.Afr. Bot. 22 : 5-22. SCH E LPE, E. 1 il70. Pteridophyta in E X E L L , A .W. & LA UN ERT, E. Flora Zambesiaca . London . TAR D I E U-B LOT, M . L . , 1 94 1 . S u r quelques Ophioglossum d e Madagascar e t des i l es voisines.

No tul. Syst. 9 J 1 1 1 - 1 1 6 . TAR D I E U- B LOT, M . L. i n H U M B ERT, H . , Flare de Madagascar e t des Comores, Paris, 1 951 -

Marattiacees, Oph ioglossacees, Hymenophy l lacees, Cyatheacees; 1 958 - Polypod iacees I ­l l ; 1 97 1 - Lycopodiacees, H uperziacees, H uperziacees.

TAR D I E U-B LOT, M . L . , 1 954. Sur les Cten itis du groupe crinita de Madagascar et des Mascareignes . Notul_ Syst. 15 : 77-85.

TAR D I E U-B LOT, M . L. , 1 954. Sur quelques Dryop teris de la Reun ion . Notul. Syst. 15 : 90-92. TAR D I EU-B LOT, M . L 1 954 . Sur les Tectaroideae de Madagascar et des Mascareignes avec

description d'un genre nouvea u : Pseudotectaria No tul. Syst. 15 : 86-90. TAR D I EU-B LOT, M . L. , 1 956 . Sur les Oleandra et les Davallia de Madagascar et des Mascareignes,

et description d'un Tectaria nouveau. Notul. Syst. 15 : 1 77-1 80. TAR D I EU-B LOT_ M . L. , 1 956. Le genre Polystichopsis et Rumohra a Madagascar et aux

Mascare ignes. No tul. Syst. 15 : 1 68-1 76 . TAR D I EU-BLOT, M . L., 1 956 . S u r les Polystichum du groupe aculeatum de la region malgache.

Mem. Inst. Se. Madag. ser_ B, 7 : 4 1 -46. TA R D I EU-B LOT, M . L. 1 957. I . Sur les A thyrium malgaches du sous-genre Diplazium . Affin ites

et description d 'especes nouvel les. Bull Mus (Paris) 19, ser. 2 : 289-293 . TAR D I EU-BLOT, M . L. , 1 959. Sur les Elaphoglossum de la region malgache avec descr iption

d'especes nouvel les . Notul. Syst 15 : 425-443. TAR D I E U-B LOT. M L. , 1 959. Les Grammitis de la reg ion malgache . Notul Syst. 15 : 421 -425. TAR D I EU-BLOT, M . L . 1 959. Combinaisons et especes nouvel les de Ctenop teris, Xiphopteris et

Microsorium de Madagascar et des Mascareignes . Notul. Syst. 15 : 443-447 . TA R D I E U-B LOT, M .L. , 1 960. Les Ptaridophytes d e I 'Afrique lntertropicale Francaise . Mem. Inst.

Fr. A fr. Noire. 28 : 1 -24 1 . TAR D I EU-B LOT, M . L., 1 960. Les F ou geres des Mascareignes et des Seychel les. Notul. Syst_ 16 :

1 51 -201 . TAR D I EU-B LOT, M . L . , 1 970. A propos des Lycopod ia les de la region malgache. A dans. 10 : 1 5-22. TAR D I E U-B LOT M . L. JAEG E R , P . & A D A M , J .G . , 1 97 . Le Massif des Monts Lama (Sierra­

Leone) , fasc. 1 , V. Pteridophytes filicales no. 86 : 1 1 3-1 77. TAR D I E U-B LOT, M . L. , N I CK LES & JACQUES-F E L I X , H., 1 949. Con tribution a la flare et

a /'eologie des fougeres du Cameroun. Etudes camerounaises 2, no. 25-26 : 8 1 - 1 1 2 .

366 F E R N G AZETTE : V O LU M E 1 1 ( PA RT 6) 1 97 8

REV IEWS

FERNS OF HONG KONG by Harry H. Edie XVIII + 285 pp., 15 pi. Hong Kong University Press, 1978. 214 x 140 mm. Price not quoted.

This is a flora of the is land of Hong Kong and that part of the China main land and offshore is lands that make u p the New Territories. Harry Edie has written this book "out of necessity" for h is u ndergraduate students and the f irst 23 pages therefore are devoted to n otes on I ife-cycle. ecology, classification morphology and evolution . These are clear and concise and w i l l be easi ly understood by amateurs and sixth-form students a l i ke . That on classification is weakest and I feel the h igher taxa cou ld have been d iscussed more fu l ly or. at least, references given to up to date work on the subject. In that on morpho logy, the variation of spore shape and wa l l structure and ornamentation is not mentioned nor i s its importance as a taxonomic character. I wou ld have l iked a paragraph on geograph ical affin ities to emphasise that some 50% of the species are south-east Asian ranging from I ndia to S . E . China and often to Ph i l i pp ines and Ma lesi a ; 1 2% are Ch inese reaching Formosa and Japan , and on ly 1 7% are confined to S E Ch ina. Two or three species are doubtfu l ly endemic.

There i s a check l i st to the 1 80 or so species covered, arranged according to R .E . Ho lttu m's account of genera for Flora Malesiana . One new combination ( Lunathyrium zeylanicum ( Hook.) H . Edie) i s made there. Keys and descriptions are good, i l lustrated with clear thumbna i l sketches by the author. Standard of binding (soft but durable) . and printing are good . I detected on ly one printing error Arachnoides instead ·of Arachniodes and perhaps 'deltoid' ( p . 1 8) shou ld be 'deltate' but these are m i nor points . Th is i s a n ice book to possess as an i n troduction to the fern flora of main land east Asia and wi l l , I feel sure, encourage the study of ferns general ly i n that part of the world.

A. C. JERMY

THE PTERIDOPH YTE FLORA OF FIJI by G. Brownlie. 397 pp. 44 plates. 175 x 250 mm. (Beihefte 55 zur Nova Hedwigia). J. Cramer, Vaduz, 1977. Price OM 200 (about £5 1. 00) Subscription price DM 160 (about £4 1.25).

The main body of th is work i s g iven over to description of fam i l ies (25) . genera (89) and species (296) of the pteridophytes found on the F ij i i s land Group. Fu l l p lace of pub l ication is g iven for each taxon but few deta i l s are given on types. The author, Garth Brown l ie, on the staff of the Un iversity of Christchurch , Canterbury. N Z , has a l ready one other fern F lora to his credit, namely that of New Caledonia. Th is reviewer wou ld have wished for a b iogeographical d iscussion on the flora of F ij i and more about the environment of those is lands; only seven pages are given over to . introductory matter.

E ighteen of the species are described here for the f irst time ( i n Belvisia, Bolbitis, Ctenitis, Ctenopteris, Elaphoglossum, Grammitis, Hypolepis, Lycopodium, Microlepia, Pteris, . Tectaria and Trichomanes) . The fol l owing new combinations are a lso made : D{cksonia moluccana Bl . var. lnermis Baker i s transferred to Dennstaedtia ; Microlepia tenu is Brack. to Orthiopteris ; Ctenitis gordoni i ( Baker) Copel . and A thyrium gi l lespiei to Lunathyrium; Dryopteris maxima (Baker) C.Chr. to Arachnoides; D. wai waiensis C.Chr. tOt Ctenitis; Lomaria col'iacea Brack., L. doodioides Brack. and L. pilosa Brack. to FJechnum; and Microsorium parksii Cope I . to Phymatosorus .

The book is of the technical standard we have come to expect from J. Cramer; clear typography and the p lates by Helime Mu lder are exception a l l y good and show useful d iagnostic features. However. one must ask the question : "For whom do we write such F loras?" For the professional botan ist, the student or keen amateur who wishes to i dentify ferns 01 i=i j i the meat of this book could have been produced for one quarter the price. A.C. JERM Y

F E R N G A Z . 1 1 ( 6 ) 1 9 7 8

A NEW SPECIES OF LOMARIOPSIS FROM MAURITIUS

DAV I D H . LO R ENCE Missouri Botan ical Garden, 2345 Tower Grove Ave .

St. Louis, MO 631 1 0 U .S.A .

ABSTRACT

A new species of Lomariopsis, L. mauritiensis Lorence, is described from Mauritius, and its ecol ogy discussed.

INTRODUCT I O N

367

During the preparation of an account of Lomariopsis for the forthcoming 'F i ore des Mascareignes' , exami nation of materia l of the genus from the Mascarene I s lands has revealed the ex istence of a new species. The genus is represented in the M ascarenes by fou r ind igenous species restricted to the is lands of Mauritius and Reun ion, none occurring on Rodrigues. The gregarious Lomariopsis pollicina (Wi l l em.) · Mett. is undoubtely the most frequently encountered species on both isl ands . l t is particu larly common on Mau ritius in lower montane wet and cloud forest formations. Young M ascarene specimens tenative ly assigned to L. buxifolia ( Kuntze) Fee (type from Madagascar) by Holttum ( 1 939) appear to represent extreme variants of L. pol/icina, which is quite pl astic in its j uven i l e form . The other th ree species of Lomariopsis are much more loca l ized in distri bution . Three col lections of L. cordata ( Bonap.) Alston , a Madagascan species, were made by Commerson (herb. Paris) on Reu n ion a lmost 200 years ago and represent the only known occurrence of the species i n the Mascarenes. L. variabilis (Wi l ld . ) Fee, with its remarkably polymorphic juven i le fronds, is presently known on ly from a single station on Mau ritius . I ts present status on Reunion is uncerta i n , having been last col lected there over one hundred years ago . F ina l ly , L. mauritiensis is apparently restricted to Maurit ius where it is l ikewise known from a single locality at present ( Lorence 1 978) .

Lomariopsis mauritiensis Lorence, sp. nov. ( F igs 1 & 2 ) Affinis Lomariopsis pol/icina (Wil lem.) Mett., differt bathyphy l l is 2-jugis dispositis, acrophyl l i s 3-6-jugatis bis la tioribus, rhachidi alata, squamis rhizomatis obscurius brunneis minoribus ( 0.5·0.8 x 7-Smm) et habitatione riparia. F rons fert i l is ignota.

TYP E : MAUR I T I US, eastern flank of Mt. Lagrave, Lorence 827 in MAU 1 6293 (MAU·holo) . PAR ATYPES: MAUR ITI US, Curepipe, Kanaka, Emmerez s.n., Aout 1 907 (P) ; Mt. Lagrave, eastern flan k, Gueho & Lorence 1638 (M O ) .

Riparian fern , rhizome dorsiventral , long-creeping, fronds two-ranked, 2-3cm distant, apex covered with soft, cur l ing, glossy medium brown scales intermixed with smaller glandular scales and hairs. Rh izome scales ( F ig. 2A) l i near-ovate to subulate, to 0.5-0.8 x 7-Smm, base truncate to rounded, apex f i l iform or sinuate with glandular tip cel l , margins subentire, bearing scattered multice l lu lar c i l ia 0.1 -0.5mm long, cel ls long-rectangular, seriate, walls dark brown, lumina pale brown. ACR OP H Y L LS: Sterile frond 1 6-35cm long. Stipe 1 2-1 7cm long, 1 .5-2.0mm diam ., dul l pale brown to stramineate, winged in upper half, wings continuing as dark l i nes to rhizome, adaxial su rface sulcate. Stipe beari n g at its base a few scales l i ke those of the rhizome but paler brown and wider (to 1 m m wide) with cordate base (F ig . 2 8 ) . Entire length of stipe bearing sparse, scattered smal l brown multicel lu lar glandular scales or hairs. Lamina ovate to ovate-el l i ptic, 1 5.5-22.5 x 1 0.0-0.1 8.0 cm, imparipinnate, lateral pinnae 3-6-jugate, articulate, subsessi le , subopposite to alternate, spaced 2.5-3.0cm on each side, the basal ones s l ightly reduced. Rachis winged, s l ightly zig-zag, adaxial surface sulcate, abaxial su rface rounded and stramineate, bearing sparse smal l brown multicel lu lar-glandular hairs scattered along its length. Largest lateral p innae ovate-el l i ptic to l inear el l iptic, sl ightly falcate, 7.0-1 0.5 x 2.0-3.0cm, apex obtuse or usually bluntly acumi nate, basiscopic side of base oblique and narrowly cuneate, acroscopic side broadl y cuneate. Costula

368 FERN GAZETTE : VO LUME 1 1 PA RT 6 ( 1 978)

raised, stramineate, adaxial surface grooved, abaxial surface rounded. Veins raised on both surfaces, simple or usually forking 1 -2 times, tips free, thickened Into hydathodes. Margin sligh tly revolute, entire, slightly slnuate, narrow, brown and cartilaginous. Lower surface of pinnae bearing scattered, adpressed brown septate glandular-tipped hairs ea 1 mm long, entire or branched (F ig 2C). Drying dark olive brown on adaxial su rface, much paler beneath . Terminal pinna not articulated, similar to laterals but larger, to 1 0-1 4 x 2.5·3.2cm, apex usual ly acuminate. Fertile frond u nknown.

BATHYPHYLLS ea 1 0cm long, stipe Scm long x l mm diam. Lamina with 2-jugate pinnae 1 .0·1 .2cm distant, subsessile, ovate-el l iptic, lateral pinnae 1 .8·2.8 x 1 . 1 · 1 .5cm, base narrowly cuneate, apex obtuse, terminal pinna larger, rachis winged.

ECOLOGY

Presently k nown only from the type l ocal ity on the eastern fl ank of Mt. Lagrave, ( alt . ea 600m) . in lo'w cl oud forest i nvaded by exotics, the new species was found to be extremely local i zed. A few plants were seen creeping over mossy rocks i n the bed of a small stream i n the deep shade of a forested ravi ne. Ferti le materia l should be sought in order to complete our knowledge of the species. The type l ocal i ty i s extremely rich in pteridophytes, some 40% of the i sland's species occurring there ( Lorence, 1 978) . The col lection m ade by D . D . Emmerez d e Charmoy i n 1 907 unfortunately g ives n o precise col l ection data, merely stating "Curepipe, Kanaka." However, these two upland local it ies are separated by about 1 Okm. the whole of' which has been more or less completely deforested, so that chances of relocating the species there are a lmost n i l . Preservation of the habitat at Mt. Lagrave i s therefore essentia l in order to e nsure the survival of this species.

AC KNOWLEDG EM E NTS

I am grateful to the cu rators of the herbaria a.t Kew, Mauritius and Paris for the loan of specimens used in this study. Warmest thanks are extended to Professor R .E . Holttum for encouragement and advice.

R E F ERENCES

HO L TTUM, R . E . 1 939. The genus Lomariopsis in Madagascar and the Mascarene Islands. Notu/ae Systematica (Paris) 8:48-62.

LOR ENCE, D.H. 1 978. The pteridophytes of Mauritius ( Indian Ocean) : ecology and distribution. Botanical Journal of the Linnean .Society ( in press) .

FERN GAZ. 1 1 (6 ) 1978 369

A NEW SPECIES OF ASPLENIUM FROM MAURITIUS

DAV I D H . LO R E NCE Mi ssouri Botanical Garden, 2345 Tower G rove Ave . St. Lou is MO 631 1 0 U.S.A.

ABSTRACT

A new species of Asplenium, A. mauritiegsis Lorence, is described from Mauritius, and i ts ecology discussed.

I NTRODUCTI O N

Asplenium is the largest fern genus to occu r on Mauritius (SW I ndian Ocean ) , constituting eleven species a n d fou r varieties o f the 1 63 pteridophytes presently known from the is land ( Lorence, 1 978) . Although Maurit ius has been we l l botanized _

s ince the 1 8th century by French , British , M auritian and other col lectors, recent intensive col l ecti ng for the forthcoming 'F iore des Mascareignes ' continues to yie ld occasional new species a nd new records for the is l and.

While on M au rit ius, I encountered an undescribed species of Asplenium on the summit of Piton du Fouge. Examination of specimens at the Royal Botan ic Gardens, Kew, M useu m N ational d H istoire N aturel le , Paris and M issouri Botanical Garden herbaria fai led to reveal a comparable species.

D ESCR IPTION

Asplenium mauritiensis Lorence, sp. nov. Species Asplenium angolense Baker affi nis ; gemmis 2-1 0 lateral ibus utroque costa pinn is lateral ibus terminalibus praesenti bus, venis proximioribus ea 1 mm distantibus, squamis rhizomatis stipi tisque maioribus integris 8-1 2 x 0.5-0.8 mm differt.

TYP E : MAURITIUS, Pi ton du Fouge, crest near summit, Lorence 1602 (holotype MO; isotypes K, MAU, P). PARATYP E : MAU R I T I US, Piton du Fouge, Lorence 1019 (MAU) ( F ig. 1 ) .

Terrestrial fern, rhizome prostrate, short�reeping, 6-7 mm diam. (excluding scales) , apex densely paleaceous, fronds caespitose, ea 5 mm distant. Scales of rhizome narrowly- to l inear-ovate, falcate, 8-1 2 x 0.5-0.8 m m, clathrate, cel l s rectangular, cell walls dark reddish-brown, lumina transparent, base truncate, sl ightly constricted, margins entire, apex long, f i l iform, tip cel l glandular. Stipe 1 1 -22 (-28) cm long, 1 .5-2.5 mm diam ., slightly swollen and stramineate at base, pale green ish-gray above, adaxial surface sulcate with low, lateral decu rrent ridges, when young bearing at base l i near-ovate scales 8 x 1 mm, clath rate, base peltate, margins entire, apex f i l iform; upper part of stipe bearing smaller curl ing or sinuate scales, the peltate, subste l late base bearing glandular-tipped ci l ia. Lamina ovate to e l l iptic, 1 8-21 (-24) x 9-14 cm, imparipi nnate, pinnae 2-4 (-5) pairs, opposite to sub-opposite, 3.5-5.5 cm distant, ascendant at 70-80° angle, subequal, the lowest pair s l ightly reduced, borne on petiolules 1 -2 mm long. Rachis flattened, winged. shal lowly sulcate near �he base, when young bearing scattered scales 1 -2 mm long with tortuous, fi l i form glandular tip, the substellate base clathrate, ovate, bearing 1 -3 pairs of glandular c i l ia. Largest pinnae 4.5-8.5 x 2.0-3.3 cm, narrowly angu lar-ovate, trullate to trapezoidal, sl ightly falcate; basiscopic side of base narrowly cu neate, acroscopic side broadly cuneate to truncate or auriculate, auricle not detached; apex bluntly acute to acuminate; margin shal lowly dentate-serrate, teeth 1 mm long, 5-6 per cm. Drying pall id chalky green; texture flexible, herbaceous. Apical pinna similar to laterals but longer and more deeply serrate or even incised. Veins forking 1 -2 times, at an angle of 30-40° with costa, tips free, ending in e l l iptic hydathodes on adaxial su rface of lamina 1 mm diatant. Both su rfaces of p innae when young bearing tiny scattered scales 1 .0-1 .5 mm long with tortuous, f i l iform glandular tips, cel l walls dark, base 0.5 mm wide, clathrate, subste l late with 1 -3 pairs of glandular-tipped ci l ia . Scales on upper surface soon caduceus. Sari 1 0-20 pairs on alternate ve i ns, often a lternately long and short, 3-1 0 mm long, s i tu<Jted midway between costa and margin, indusiu m· 0.5-0.6 mm wide, l inear, falcate, white, membranous, not reflexed at matu rity. Mature plants gemm iferous, adaxial surface of pin nae each bearing 2-1 0 gemmae along either side of costa.

370 FERN GAZETT E : V O L U M E 1 1 PA RT 6 ( 1 97 8 )

IOCft\

FIGURE 1 . Paratype of Asplenium mauritiensis Lorence from Pi ton du Fouge, Mauritius (a lt.ca 650 m ) . Note abundance of gemmae and thei r lateral position along costa

on both terminal and lateral pin nae .

A F F I N I T I ES

The new species is most c lose ly a l l ied to and indeed strongly

resembles Asplenium angolense Baker from Kenya and Uganda in terms of gross morphology . I n fact, I was a t f i rst incl ined to regard the two as conspecific, d iffer ing at an infraspecific leve l . However, c loser examinat ion has revealed a number of more important differences. Most stri k ing a re the d ifferences i n scales. I n A . mauritiensis scales from the rhizome and base of stipe a re much larger (8- 1 2 x 0.5 -0.8 mm), narrowly to l inear­ovate, with ent ire margins and long-rectangular ce l l s, but in A. angolense they are tiny ( 1 -2 x 0.5 m m ) ovate-deltoid with glandu l ar-c i l i ate margins and short, squarish cel ls. Both species are gemmiferous, but Faden ( 1 973 and pers. com m . ) notes that A. angolense produces on ly a s ing le gemma media l ly on the upper surface of the termina l p inna, wh i l e i n A. mauritiensis from two to ten gemmae are produced on both sides of the

costa on the termina l and frequently the l ateral pinnae as wel l The veins on A. angolense are spaced about 2 mm distant but are only about 1 mm apart i n A. mauritiensis. Although c losely al l ied to A. angolense, these d ifferences are sufficiently important for the Mau ritian pl ants to merit specific status . Fern scales provide excel lent d iagnostic features and are critical to the taxonomy of the group.

ECO LOGY

Piton du Fouge is one of the h ighest peaks of the soLJthernmost f lan king mounta in range, ea 650 m , and is the on ly known l oca l ity for A. mau;itiensis. The peak represents an eco logica l ly u n ique situation for the is land. I ts extreme southwestern position provides it with ra infa l l of 1 800 mm per year carried by the southeast trade winds, sign ificantly h igher than that rece ived by adjacent mountains, and subjects it to comparably h igh temperatures

A single extremely loca l i zed colony of about 20-25 plants of A. mauritiensis measur ing about 30 x 1 0 m was found growin g a long the crest just below the su mmit in moderate shade of a low montane evergreen forest dominated by Diospyros tesellaria Poi ret, Securinega durissima Gmel in and Nuxia verticillata Lam . Asplenium auritum Sw., A. nitens Sw. and A. viviparum ( L.f.) Presl var. viviparum were also l oca l ly common as ground ferns or growing at bases of trees.

LO RENCE: N EW ASPLEN I U M F ROM MA U R IT I U S 37 1

The presence of th is u n ique colony of A. mauritiensis on Maur it ius seems to

ind icate extreme ecological speci f ic ity . Reproduction in the sma l l col ony may be

exclus ively vegetat ive ; the occurrence of p lantlets growing from fa l len gem mae arou nd mother p lants was com mon . Although the colony appears to be i n no immediate

danger, preservatio n of the habitat at P iton du F ouge is i mperat ive in order to ensu re

survival of the spec ies.

R E F ER E N C ES

F A D E N , R .B . 1 973 . Some n otes on the gemmiferous species of Asplenium in Trop ical East Africa. Am. Fern Jour. 63(3) : 85-90.

LOR ENCE, D . H . 1 978. The pteridophytes of Mauritius ( Indian Ocean) : ecology and distribution. Bot. J. Linn. Soc. ( in press ) .

REV IEW

THE BIOL O G Y OF BRA CKEN - Edited by F.M. Perring and B. G. Gardiner for the

Linnean Society of London. Bot. J. Linn. Soc. Vol. 73 nos. 1, 2 & 3 ( 1916) pp. viii + 302. Academic Press. London. 257 x 180 mm. £13.20

Th is su bstant ia l vo lume is the resu l t of a Symposiu m on the b io logy of Pteridium

aquilinum ( L . ) Kuhn he ld i n London on 3rd and 4th September 1 974. l t is we l l edited

and n icely executed to the standard we except from the Linnean Society and

Academ i c Press.

The m ost s ignif icant papers for the pter ido log ist are those on the Taxonomy and

phytogeography by C . N . Page {pp. 1 -34) . and on Chemotaxonomy and

phytochem ical ecology by G. Cooper-Driver ( 35-46) . Page reviews morophological

and cyto logica l ev idence for the phylogenet ic aff in it ies of the genus and concludes

that a l though related poss ib ly to Den nstaedt iaceae i t shou ld perhaps be p laced with Paesia and Hypolepis in a separate fami ly , the Hypolep idaceae. Unfortu nately due to

the restricted amount of work on other genera th is cou ld not be su bstantiated

chemica l ly by Copper-Dr iver . The i nfra-specif ic taxonomy d i scussed by Page is based

predominant ly on R . Tryon (Rhodora, 43: 1 -3 1 , 36-67 ; 1 94 1 ) and whi l st the

geography of each of the twelve varieties is f u l l y d iscussed the morphology and

d isti nctions of each are not. Th i s cou ld , of cou rse, have been bor ing in a del ivered paper but the reviewer wou l d have found a key to var ieties very usefu l i ndeed in th is

printed account.

Peter Be l l and J .G . Duckett g ive a deta i l ed account of ( pp . 47-78) the pr inc ipa l

events in spermatogenes is and oogenesis and po int out the para l le l s of the

spermatozoid with the moti l e ce l l s of chaetophoralean a lgae . The chemistry of bracken

is d i scussed a great length in five papers. The reason why bracken is so we l l studied in

th i s f ie ld is I suspect because of its abu ndance and a l so because it i s an econom ical l y

importance pest . H .J . Duncan and M .C. Jarvis { pp 78-85) d iscussed t h e role o f sugar

nucleotides; G . H . W i l l iams and A. Fo ley {pp 87-93) showed that a knowledge of

seasonal var iat ion in carbohydrate content i s i mportant for contro l l i ng by cutt ing and

herbic ide-appl icat ion ; S . R. G l iessman showed {pp 95- 1 04 ) how tox i ns released by

dead bracken frond a l low the plant to assert i ts dominance over associ ated p lants. An

enzyme, th iam i nase, wh ich destroys th iamine is the ma in contr i butor to the po isonous

effect of bracken on a n i ma l s accord ing to W .C. Evans { pp . 1 1 3-1 3 1 ) ; other substance ,

among them sh i k i m ic ac i d , are shown b y I .A . Evans { p p 1 05- 1 1 2 ) to cause cancer and

the poss ib i l i ty of a n env ironmental human hazard must not be ru l ed out .

372 F E R N G A Z E T T E : V O L U M E 1 1 P A R T 6 ( 1 978)

Four papers d iscuss the eco logical role of bracken . The most important is that by Alex Watt (pp 2 1 7-239) who has spent a l ifetime studying the species - and it is main ly thanks to him that th is symposium contains the contr ibutions it does. He po ints out that where l i tter formed in the bracken stand exceeds loss through natural decomposit ion, bracken may become the victim of its own success through having to recycle the nutri ents of its own tissues. S.A. Hutchinson showed (pp 1 45-1 50) the effects of Fungi on bracken and J .C. F rankland (pp 1 33- 1 43) showed that whi l st read i ly leached components (Na , K and P) may be removed from dead fronds within a few months the main body of stipes and rhach ides took 1 1 - 23 years - hence the value of bracken peat to the h orticu lturist and bracken straw to the farmer as bedding for an imals . The l atter reminded the reviewer of being shown a stand of bracken on an estate in the I s land of M u l l wh ich was conserved for its use in the cow-shed, there be ing l ittle other on the estate of 200 ha ! J . H . Lawton described (pp 1 87-2 1 6) the one important an imal commun ity , namely the arthropods and their relat ion to seasonal change.

The control of bracken is briefly discussed by D.J . Marti n (pp 24 1 -246 ) . P. Veerasekaran , R .C . Ki rkwood and W .W. F letcher describe (247-268) the mode of action of Asulam, the herbicide whi ch the agricultur ist bel ieves spel l s salvation and which the pter idolog i st fears bodes i l l for the conservation of other species of ferns which are a lso ki l led regardless. I .A. N icholson and I .S . Patterson discuss (pp 269-283) the ecological i mpl ications of bracken contro l to pl ant/an imal systems. They est imate that bracken herbicide is u n l ike ly to be used on more than 25% of Scotland's bracken coverage because of the cost of the produce and its appl icat ion, and that w i ld vertebrate popu lations are not in jeopardy. In a paper on the botan ical impl ications of bracken control (pp 285-294) C.J. Cadbury considers Asu lam to be a usefu I aid to the management of nature reserves where bracken needs to be contro l l ed but emphasies that ind iscr iminate aer ia l spraying can be detrimenta l .

Lastly two papers were presented on the h i story of the occu rrence and use of bracke n . M . R . D . Seaward reported (pp 1 77- 1 85) the occurrence of bracken in the pre-Hadrianic deposits at V indolanda, Northumberland and L. Rymer, i n a very readable and interesting paper (pp 1 5 1 -1 76 ) , rev iewed the uses and ethnobotany of th is fern we now come to know as a pest.

The volume reviewed above is a compend ium on Pteridium acquilinum and a l l bio logical a n d agricu l tura l research institutes and l i braries shou ld , i f they are not subscribers of the Linnean Society of London, obta in it.

A.C. J E R M Y

FE R N GAZ. 1 1 (6 ) 1 9 7 8

F IRE-RESISTANCE IN THE PTERIDOPHYTES OF ZAM BIA

JAN KO RNAS Institute of Botany, Jage l lon ian Un iversity,

u l . Lubicz 46. 3 1 -5 1 2 Krak6w, Poland

ABSTRACT

Observations have been made on the incidence of burning in various types of habitats occupied by the pteridophytes in the savanna woodland zone of Zambia, and the relevant herbarium col lections have been chec ked for f i re-scars. No less than one fifth of all pteridophyte species in the study area p roved to be able to survive repeated bu rning, and some of them possess morphological and biological features of advanced pyrophytes. Problems of origin and evol ution of the pyrophytic habit in the pteridophytes are briefly discussed.

I NTRODUCT I O N

373

F ire is commonly recogn ized as a master factor shaping the vegetation in seasonal ly dry parts of tropical Africa. Various types of savanrias and savanna woodlands of this immense area are believed to be fi re-c l imaxes ( Fanshawe 1 97 1 , Hopk ins 1 963, Knapp 1 973, Ph i l l ips 1 974, West 1 972), and many plant species occurring there possess pecu l iar morphological and biological features wh ich enable them to persist under recurrent burn ing (Cole 1 974, Exel l and Stace 1 972, Jackson 1 974, West 1 972) . Such pyrophytic adaptations, however, have been studied so far only in the phanerogams, and almost noth ing is known about the effects of burning u pon the pteridophytes growing in f i re-affected habitats i n tropical Africa and elsewhere. The scope of the present paper i s to contribute towards f i l l ing th is gap and to present an evidence as to the importance of the f i re factor in the l ife of ferns and fern-al l ies in Zambia .

STUDY A R EA

Zambia is s ituated i n the very heart of the Zambezian Domain of the Sudano-Zambezian Phytogeographical Region (Wh ite 1 965, Chapman and White 1 970) . lt has a typical tropical savanna c l imate (type Aw in Koppen's system, type 1 1 i n Waiter's cl assificat io n ) , with a warm rainy season between N ovember and Apr i l , and a long dry season , cool at the begi n n ing (May-July ) , but becoming more and more hot towards the end. (Augusf-October) . The annual rainfa l l i s more than 1 200 mm in the north decreasing gradual ly to 800 mm or l ess in the south , i n the Zambezi and Luangwa va l leys. The dry season i s the burn i ng time for vegetation and most of the country, except for farmland and l and with permanently wet soi l s, fa l l s prey to f i re before the new rains start.

The ma in vegetation types occurring in Zambia have been recently described by Wh ite ( 1 969) and Fanshawe ( 1 97 1 ) . Savanna woodlands occupy the majority of the territory, especia l ly on the vast expanse of the Central African Plateau. Savannas and flood-pla in grasslands are also fai rly common, wh i le other vegetation types are confined to small areas with unusual conditions of moisture and soi l s .

The Zam bian f lora is rather poor i n ferns and fern-al l ies. Only 1 44 species have been found to occur tliere (Schelpl! 1 970, Ktirna� f974. i 9761 . many of them very rare and strictly l i m ited to the h igher rainfal l areas in the northern part of the country . Many species show a decided preference for rare extrazonal commun ities of specia l habitats (e.g. evergreen forest patches) or for the earl ier successional stages i n both xeroseres (on rocks) and hydroseres. Very few pteridophytes occur i n mature stands of near-c l imax woodland commun ities.

FIGURE 1 . Cheilanthes angustifrondosa with fire-scars on stipes of the previous year. Zambia, Northern Province, Kalambo Falls,

7 Apr i l 1 973. J. Kornas PI. A fr. 3662 ( KRA) .

. - ·--·- ···

FIGURE 2. Dryopteris athamantica with f ire-scars on stipes of the previous year. Zambia, Central Province, near Serenje, 3 February

1 973 . J . Kornas PI. Afr: 3 1 4 1 (KRA).

w -...J �

"'11 fTl :c 2 G) l> N fTl -1 -1 fTl < 0 r c � fTl

'tl l> :c -1 en .... 10 ..... "'

KO R N AS: F I R E- R ES ISTANCE IN ZAM B I A N PTER I DOPHYTES 375

MATER I A LS AND M ETHODS Fie ld data on "the incidence of fires i n var ious types of habitat and on the effects of burn ing upon the pteridophytes have been coll ected between August 1 97 1 and Ju ly 1 973 during extensive trips throughout Zambia ( except the Western and Luapu la Provinces - fig. 16 A). These observations have been subsequently confi rmed and supplemented through the study of herbarium specimens from Zambia in the author's coll ection deposited at the I nstitute of Botany of the Jage l lon ian Un iversity of Krak6w ( KR A *, dupl icates in AAU, B R , EG R , G, K, MO, N DO, '-!SW, and the University of Zambia Herbar ium, Lusaka ) , as wel l as in the herbaria of the Royal Botanic Gardens, Kew ( K ) , British M useum (N-atural History ) , London ( B M ) , Commonwealth Forestry I nstitute, Oxford ( F HO). and the East African Herbar ium, Nairobi ( EA ) . Every complete specimen of a pteridophyte with its u nderground parts properly preserved has been carefu l ly checked under the binocu lar m icroscope for fi re-scars. This is a very s imple and rel iable test for detecting bu rn ing marks from the previous season whicti usual ly appear very clearly as charred remnants of old stipes, more or less even ly cut near the ground-l evel (figs. 1 - 1 5 ) . There is, however, one serious l im itation to this test: i t is appl icable only to those pl ants in which some l iv ing or dead above-ground organs normal ly persist through the dry season of the year. Plants with thei r perenati ng organs h idden under the ground (geophytes) do not usually bear any fi re-scars even when growing in pl aces evidently burnt in the last dry season. Therefore the real number of species which survive the fi res is certa in ly h igher than that confi rmed through the study of herbariu m spec imens.

·

The species l i m its and nomenclature adopted in the present paper are those proposed by Schelpe ( 1 970) .

R ESU LTS Numerical data concern i ng fi re-scarred specimens found in the herbarium col lections of pteridophytes from Zambia are presented in table 1 . All in all 23 species (22 ferns and .1 club-moss ) are l i sted , i .e. a lmost 1 6% of the total number of 144 species of ferns and fern-al l i es known to occur in that cou ntry . Accordi ng to the field notes, half a dozen or so fu rther species, mostly geophytes (Pteridium aquilinum ( L . ) Kuhn, Nephrolepis undulata (Afz. ex Sw. ) J .Sm . i n Curt . , Ophioglossum spp. , etc.) have also been observed to persist i n recently burnt pl aces. Thus, a surprisingly h igh number of Zambian pteridophytes prove to be able to su rvive burn ing, e ither at annual i ntervals or at least occasional ly . The majority of them bel ong to the species most widely d istributed and most abundant throughout the country, a fact which strongly suggests a very high importance of f i re as a l imit ing factor for pteridophytes in the study area.

The species l i sted in table 1 occur only in a small number of habitat types: rock crevices, savanna woodlands, forest edges and "dambos" (i e. grass lands of flat depressions, wet at least i n the ra iny season ) . The incidence of fi res is very h igh in al l these places but there are essential d ifferences between them in the ecological effects of burni ng.

The savanna woodlands of the "m iombo" type, which are the dominant vegetation over most parts of upland Zambia, are usually burnt each year i n the dry season. The f ires are rather l i ght, sweep fast over the ground, and consume only the ground l ayer of vegetation leaving the trees and shrubs more or less u ndamaged . In the ground layer, however, al l dry plant materia l , i nc luding grass, tree l eaves and twigs, is burnt fa ir ly completely. Herbaceous pl ants occurring in such places have to survive

* The herbarium abbreviations a re those p roposed by Holmgren and Keuken ( 1 974 ) .

376 FERN G A Z ETT E : V O L U M E 11 PART 6 ( 1 9 78)

Collections examined

total with fire scars Habitats Species

nu m- nu m-%

ber ber

Actiniop teris dimorpha P .Serm . 7 4 57.1 rocks Actiniop teris pauciloba P .Serm . 1 3 9 77.8 rocky m iombo Actiniop teris radia ta (Sw.) Lin k. 1 2 1 8 .3 rocks Actiniop teris sp. indet. (main ly hybrids) 1 2 7 58.3 rocks, rocky miombo Adiantum incisum Forsk. 21 3 1 4.3 rocks Anemia angolensis A lston 1 6 1 2 75.0 rocl<y miombo Arthropteris orien tal is (J.F .Gme l . ) Posthumus 37 4 1 0.8 rocky m i ombo Aspidotis schimPf;ri ( kunze) P :serm. 20 8 40.0 rocky m i ombo Asplenium buettneri Hieron. 14 2 1 4 .3 rocks A thvrium schimperi Moug. ex Fee 9 2 22.2 forest edges Cheilan thes angustifrondosa Alston 2 2 1 00.0 rocky m i ombo Cheilan thes inaequa/is ( Kunze) Mett.

var. inaequalis 25 9 36.0 rocks Cheilanthes multifida (Sw.) Sw. 1 4 2 1 4.3 forests, rocks Cheilan thes similis Bal lard 4 2 50.0 rocks Dryop teris a thaman tica ( Kunze) K untze 1 2 4 33.3 miombo (ditches) Dryop teris inaequa/is (Schlechtend.) Kuntze 7 1 1 4.3 forest edges Lycopodium carolinianum L. var . tuberosum

(Welw. et A .Braun ex Kuhn) Nessel 4 1 25.0 dambos Mohria ca ffrorum ( L.) Desv. 2 2 1 00.0 rocky m iombo Mohria Jepigera (Bak. ) Bak. 1 7 9 52.9 rocks Pel/aea calomelanos (Sw.) L ink. 4 2 50.0 rocks Pel/aea Jongipi/osa Bonap. 38 33 86.8 rqcky m i ombo Pel/aea pectiniformis Bak. in Hook. 27 1 0 37.0 rocks Pel/aea viridis ( Forsk.) Prantl i n Engl . var.

glauca (Sim) Sim 5 1 20.0 rocks Pellaea viridis ( F orsk.) Prantl i n Engl . var.

involuta (Sw.) Schelpe 1 1 1 00.0 rocks Thelypteris confluens (Thunb.) M orton 30 1 3 .3 dambos

Total 353 1 32 37 .4

TAB L E 1 : F ire scars in fern specimens col lected in Zambia

burn ing every year. M iombo woodlands on deeper soi l s are usual ly completely devoid of pteridophytes, most probably because of the presence of a dense cover of h igh ly competitive grasses. In the moister regions of the country h owever, espec ia l ly at h igher altitudes, Pteridium aqui/inum (a rh izome geophyte)· may be abundant or even subdominant in th is type of environment. The bracken seems to be perfectly fire-resistant there , as e lsewhere in the world (Tardieu-Biot et a l . 1 97 1 : 1 27, Tryon 1 94 1 : 20, 29, 45, 50) . Another large terrestr ia l fern occasional ly found in the m iombo stands on deeper soi ls is Dryopteris athamantica (f ig. 2 ) . lt grows there, however, al most always in d itches or holes, its rh izome several centimeters be low the level of the surrounding woodland-floor. This seems to assure both bare humid soi l for deve loping gametophytes and additional fi re protection for perenati ng organs of the mature sporophyte.

On sha l low soi l s of steep slopes and rocky ridges the m i om bo woodlands become more open and their grass cover more scarce. In such places smal l xerophytic ferns are commonly found which represent the l i fe form of hemicryptophytes (Aspidotis schimperi - fig. 3, Pel/aea longipi/osa - fig. 4, Anemia angolensis - fig. 5 ) or an

KORNAS: F I R E- R ES ISTANCE I N ZAM B I A N PT E R I DOPHYTES

intermediate type between hem icrypt­ophytes and geophytes with the perenating buds h idden under a th in layer of soil (Arthropteris orientalis -

fig. 6) . They are the most regularly subject to annual burn ing of a l l the Zambian ferns and, according ly, fi re­scars are fou n d in more than ha lf of the herbarium col l ections of th is group (fig. 17 A) (the lower share of scarred specimens in Arthropteris orienta/is bei ng obv iously due to the nearly­geophytic habit of th is species) . Rarely the fol lowing hemicryptophytic fe rns may also be encountered in th is type of habitat: Cheilanthes angustifrondosa (f ig. 1 ) . Actiniopteris pauci/oba (f ig. 7 ) , a n d Mohria caffrorum (f ig. 8 ) .

Rock outcrops outside woodland may a lso be burnt each year. However, the i r vegetation is usua l ly scarce enough to make the f i re very patchy and i rregu lar. Consequently , numerous smal l spots in the bu rnt areas are left untouched. Therefore there i s always the l ikel ihood that a number of

377

I�

ind iv idual pl ants wi l l not catch f i re F I G U R E 3 . Basal parts of a specimen of Aspidotis every year. Th is i s clearly reflected i n schimperi col lected i n the rainy season and bearing

Table 1 in that the rock-inhabiting f ire-scars on stipes of the previous year. Za"1"re, Shaba,

species are characterized by the K ipopo, 7 December 1 970. S . Lisowski 1 0064 ( KRAl.

presence of f i re-scars i n only one tenth to one th i rd of col lections (f ig. 1 7 B ) . A l l the fern species found in rock crevices are typica l ly xeromorphic and represent the l ife form of hemicryptophytes (Actiniopteris dimorpha, A. radiata, Cheilanthes inaequalis - f ig . 9, Mohria lepigera - fig. 1 0, Pellaea ca/omelanos - fig. 1 1 , P. pectiniformis - fig. 1 2, P. vi rid is agg. , etc . ) .

The dambo grasslands are usual ly completely burnt each year. However the only pteridophytes found there belong to the geophytes (The/ypteris confluens, an obl igate geophyte - fig. 1 4, L ycopodium carolinianum var. tuberosum , a facu ltative geophyte - Kornas 1 975, figs. 1 -6 ) and therefore only exceptiona l ly retain the f ire-scarred parts unti l the next rainy season .

The mesic habitats of forest edges are normal ly situated just on the border- l ine between burnt and u n burnt areas. That is why the ferns growing i n these pl aces (A thyrium schimperi - f ig._ 1 5 , Dryopteris inaequalis , etc.) only seldom catch fire. Between one tenth and one fifth of the ir col lections have been found with scars.

lt is h ighly s ignificant that no fi re-scars have ever been found in species growing in other habitats than those a l ready d iscussed. True forest ferns, both terrestr ia l and epiphytic, which occur in evergreen montane forests, riverside forests, "mushitu " swamp forests, etc., never show even the s l i ghtest evidence of fi re-damage. Th is is also true of epiphytes (Pieopeltis excavata (Bory ex W i l l d . ) Sledge, P. macrocarpa (Bory ex Wi l ld . ) Kau l f . ) in the mist-affected m i om bo patches on h i l l tops, although these stands

378 FERN GAZETT E : V O L U M E 1 1 PART 6 ( 1 97 8 )

!�

F I G UR ES 4 & 5. Basal parts of fern specimens from Zambia, col lected in tl)e rainy season and bearing f ire-scars on stipes of the previous year (al l specimens housed in KRA) . 4, /ongipilosa. Central Province, Lake Mulungushi , 27 December 1 97 1 . J.Kornas PI . Afr. 0725. 5, Peliaea Airemia angolensis. Central Province, near Lusaka, 4 March 1 972. J . Kornas P I . Afr. " 1 326.

are burnt regularly at annual i ntervals . Obviously, the surface fi res have no i nfluence on the epiphytes growing in the tree crowns two metres and more above the ground. Neither have f ire-traces been detected i n species of humid rocks (e.g. near waterfa l l s ) , and rocky river banks- (and, of course, i n true water ferns growing in l akes, pools, s luggish river arms, etc. ) . All species confined to such habitats are apparently more or less fi re-tender. This is certa in ly the case with ferns of the evergreen forest which i nevitably perish after burn ing, along with other components of this ecosystem. Al l in a l l fi re-tender species certa in ly form the vast majority of the Zambian fern flora .

D I SCUSSION

The fi re-resistance characteristic of a number of ferns in Zambia is based on various morphological and biological features of these species. Al l of them are more or less typical xerophytes and d isplay a strict seasonal per iodicity, with a long and very pronounced dormancy period during the dry season. The renovating buds are produced either below the ground ( i n true geophytes e.g. Pteridium aquilinum, Nephrolepis undulata, etc . ) or just at the ground-level (in hemicryptophytes e.g . Actiniopteris spp., Cheilanthes spp., Pellaea spp., etc . ) . I n the l atter group the buds are

" -KO RNAS: F I R E-.R ES ISTANCE I N ZAM B I A N PTE R I DOPHYTES 379

F I G U R ES 6-8. Basal parts of fern specimens from Zambia, col lected i n the rainy season and bearing fi re-scars on stipes of the previ ous year (all specimens housed i n K R A ) . 6, Arthropteris orientalis. Central Province, Kunda l i l a Fal ls , 1 7 January 1 972. J . Kornas P I . Afr 0888. 7, Actiniopteris pauciloba. Eastern Province, Kachalola, 4 March 1 973. J . Kornas P I . Afr . 34 1 2. 8,

Mohria caffrorum. Central Province, Kunda l i la Fal ls, 5 May 1 972. J .Kornas PI . A fr. 1 666.

always deeply h idden between old stipe bases, and usual ly covered with a dense, thick coat of scal es (particular ly conspicious in Cheilanthes inaequalis - fig. 9, and Dryopteris athamantica - fig. 2 ) . Sometimes, e.g. in Anemia anglensis (fig. 5) and Actiniopteris pauci/oba (f ig. 7 ) , a tunic- l ike structure results; s imi lar to that in the South American Anemia species mentioned by Eiten ( 1 972: 303) All these characters may have orig inated as adaptive responses to severe seasonal drought and only subsequently have become also effective as means of protection aga inst fi re. We cannot, however, exclude the poss ib i l ity that f i re has also been d i rectly acting as an

380 F E R N GAZETT E : V O L U M E 1 1 PART 6 ( 1 9 78)

I�

F I G U R ES 9-13. Basal parts of fern specimens from Zambia, collected in the rainy season and bearing fire-scars on stipes of the previous year {al l specimens housed in KRA) 9, Cheilanthes inaequalis var. inaequalis. Northern Province, Bwingi Mfumu Hi l l s , 1 8 January 1 972. J. Komas PI . Afr. 0934. 1 0, Mohria lepigera . Northern Province. Mt.. Sunzu, 6 April 1 973 . J. Kornas PI . A fr. 3635. 1 1 , Pellaea calomelanos. Southern Province, Changa, 1 3 February 1 973. J . Kornas PI . Afr. 3278. 1 2, Pellaea pectiniformis. Copperbelt Province, N of Kapiri Mposhi , 30 March 1 972. J . Kornas PI . A fr. 1 486.

1 3, Adiantum incisum . Central Province, Sanje, 9 March 1 972. J. K.ornas ":.' - A fr. 1 359.

KO R NAS: F I R E- R ES ISTANCE IN Z A M B I A N PT E R I DOPHYTES 38 1

I

'-

/

1 5

FIGUR ES 1 4 & 1 5. Basal parts of fern specimens from Zambia, co l lected i n the rainy season and bearing fire�cars on stipes of the previous year (all specimens housed in K R A ) . 1 4 , The!yp teris conf!uens. Central Province, between Undaunda and Rufunsa, 2 January 1 9 72. J . Kornas P I . Afr. 0779. 1 5, A thyrium schimperi. Central Province, Kunda l i l a Fa l l s , 1 7 January 1 972. J . Kornas P I .

Afr. 0890.

evo h .itlonilry. factor, stimu lating mutation and e l i m inat ing fi re-tender pl ants from

places regu lar ly affected by burn ing . At present i t certa i n l y excerts an extremely

strong selective pressure on the vegetation of the up land habitats of savanna

woodlands. Very few ferns are able to persist in such habi tats, but those which manage it, e .g. Pellaea longipilosa , Anemia angolensis, Actiniopteris pauciloba , Pteridium aquilinum, Arthropteris orientalis, etc . . may be regarded with every reason as true

pyrophytes. In two genera of Zambian ferns, pyrophytic species ex ist which c losely resemble

those without pyrophytic habit : Arthropteris orientalis i s a counterpart of A.

monocarpa (Cordem .) C . Chr. , and Cheilanthes inaequalis i s apparently �ery near to

Ch. /aechii Schelpe. This gives the opportunity to make i nterest ing comparisons .

'tr_:- L. ,� 2�0 . ]� '�O k"' ,. n

F I G U R E 1 6. A - Routes of the author's collecting trips i n Zambia. B - Local ities in which f i re-5carred speci mens of pteridophytes have been collected in Zambia : a - 1 collection , b - 2 collections, c - 3 collections, d - 4 collections, e - 5

collections.

F I G UR E 1 7 . Distributions of Pel/aea longipilosa, a fern of open miombo woodland (A) and Cheilanthes inaequalis, a fern of rock crevices ( B ) in Zambia : a - localities in which fi re-5carred specimens have been col lected, b - other l ocalit ies . Records from l i terature, field notes and herbarium specimens without

underground parts have been disregarded.

-� 1\.)

"T\ CT1 :XJ z

Gl ·)> N CT1 ., ..., CT1 < 0 r c $ CT1 ... ...

:g :XJ ., m ... "' " "'

KO R N AS : F I R E- R ES I STANCE IN ZA M B I AN PT E R I DOPHYTES 383

Arthropteris monocarpa is an epiphyte of the evergreen forests, with more or l ess continuous growth throughout the year . it produces renovating buds, without specia l protective structures, on the tops of long rh izomes creeping widely on the su rfaces of tree trunks. Thus it represents the l ife form of a phanerophyte . I ts l eaves are larger and much more del icate than those of A. orientalis. Cheilanthes /eachii occurs in shaded rock crevices, usua l ly in places where, in the rainy season at least, some water is constantly dripping. i t has a pronounced dormancy period during the dry months, but does not produce tun ica-l i ke structures around the perenating buds . I ts leaves are much thinner and less hairy than in Ch. inaequalis and it is reproducing free ly by gemmae aris ing in the apical parts of the leaves. Th is way of vegetative reproduction is known only in ferns of humid habitats and certa in ly wou ld be a complete fa i l u re i n fi re-affected places. Thus, the d ifferences between closely s im i l a r pyrophytic and non-pyrophytic fern species turn out to be those between the xerophytes and the mesophytes. it seems that a deta i led comparative morphological and ecolog ical study of both pai rs of species discussed above as wel l as of other s imi lar cases from outside the f lora of Zambia, could be especia l ly he lpfu l for an understanding of the nature and origin of the pyrophytic habitat in ferns.

Fi re-scarred pter idophytes have been found all over the territory of Zam bia (figs. 16 and 1 7 ) . They are , however, especia l ly frequent in the drier areas of the southern and central parts of the country . The species with most advanced pyrophytic features (e .g . those from the genera Actiniopteris, Chei/anthes, Mohria , and Pe/laea ) seem a l l to belong to the same geographical and ecological element of the "afri kan ische SOd- und Randflora" as defined by Christ ( 1 9 1 0: 259) .

I n the present paper the problem of fire-resistance and pyrophytic adaptation i n ferns has been discussed only i n relation to mature sporophytes. However, the gametophytic phase is certa in ly the most critical stage in the l ife h i story of every pteridophyte. No sexual reproduction is possi ble, even in the most extreme xerophytes, in the absence of l iqu id water. The protha l l i a are genera l ly more del icate and more suscepti ble to adverse envi ronmental conditions than the sporophytes. (However, many xerophytic ferns, e.g . from the genera Cheilanthes and Pel/aea , are able to produce sporophytes apogamous ly, and this is be l ieved to be an adaptive feature particu lar ly important in dry environments (Hevly 1 963 ) ) . it certa in ly wou ld be an excit ing task to study the germination of spores and the survival of gametophytes, as wel l as thei r reproductive b io logy, in pyrophytic ferns growing under natu ral cond itions and subject to repeated burni ng.

ACKNOWLEDG EMENTS The f ie ld work for the present paper was supported by the Research and Higher Degrees Committee of the University of Zambia, Lusaka. The manuscr ipt was prepared under a grant of the Committee of Botany, Pol ish Academy of Sciences, Warszawa. The study of the herbar ium col lections in Britain was made poss ible through a British Counci l vis itorsh ip . The East African Herbar ium, Nairobi , was vis ited when the author was participat ing in the Pol ish East Africa Expedition, "Ki l imanjaro 75". Thanks are extended to the curators of a l l the herbaria mentioned for the i r k ind assistance, to M iss G. Ha lastra, M .Sc., for techn ical a id , to M rs . E. Nowotarska, M .Sc . , who drew the f igures, and to Mr . Z. Dzwonko, D .Sc , who took the photographs .

R EF ERENCES CHAPMAN, J .D . & WHITE F. 1 970. The e vergreen forests of Malawi. 1 90 pp. Commonwealth

Forestry I nstitu te, Oxford.

384 F E R N G A Z ETT E : V O L U M E 1 1 PA RT 6 ( 1 9 7 8)

C H R I ST, H . 1 91 0. Die Geographie der Fame. 358 pp. Gustav F ischer, Jena. CO LE, N . H.A. 1 974. Cli mate, life forms and species d istribution on the Loma Montane grassland,

Sierra Leone. Bot. J. Linn. Soc. 69 : 1 9 7-2 1 0. E ITEN, G. 1 972. The cerrado vegetation of Braz i l . Bot. Rev. 38: 201 -34 1 , EXELL, A.W. & STAGE C.A. 1 972. Patterns o f distribution in the Combretaceae. I n :

Taxonomy, Phytogeography and Evolution (ed. D.H. Valentine), pp. 307-323. Academic Press, London and New York.

FA NSHAW E, D.B. 1 9 7 1 . The vegetation of Zambia. Republic of Zambia, Minist. of Rural Deve/opm., Forest Res. Bull. 7: 1-67.

HOLMGREN, P .K. & KEUKEN, W. 1 974. Index Herbariom. Part 1. The herbaria of the world Sixth ed. V I I + 397 pp. Oosthoek, Scheltema and Holkema, Utrecht.

JACKSON, G. 1 974. Cryptogeal germination and other seedl ing adaptations to the burn ing of vegetation in savanna regions: the origin of the pyrophytic habit. New Phytol. 73: 771 -780.

HEVL Y, R . H. Adaptations of cheilanthoid ferns to desert envi roments. J. Arizona Acad. Scie 2: 1 64- 1 75.

HOPK I NS, B. 1 965. Forest and savanna. An introduction to tropical plant ecology with special reference to West A frica. X I I + 1 00 pp. Heinemann, lbadan and London.

KNAPP, R. 1973. Die Vegetation von A frika, unter Berucksichtigung von Umwelt, Entwicklung, Wirtschaft, Agrar- und Forstgeographie. X L I I I + 626 pp. VEB Gustav F ischer Verlag, Jena.

KO RNAS , J . 1 974. The Pteridophyta new to Zambia. Bull. Acad. Polon. Sci, Ser. Scie. Bioi. 22:

71 3-7 1 8. KORNAS , J. 1 975. Tuber production and fi re-resistance in Lycopodium caro/inianum L. in Zambia.

Acta Soc. Bot. Po/oniae 44: 653-863. KORNAS, J. 1 976. The Pteridophyta new to Zambia. 1 1 . Bull. Acad. Polon. Sci. Ser. Sci. Bid/. 24: P H I L L I PS, J. 1 974. Effects of fire in forest and savanna ecosystems of Sub-Saharan Afrka. I n :

Fire and ecosystems (eds. T.T. Kozlowski, C.E. Ahlgren ), pp. 435-481 . Academic Press, New York. etc.

SCH E LPE, E.A.C.L.E. 1 970. Flora Zambesiaca. Pteridophyta. 254 pp. Crown Agents for Oversea Governments and Admin istrations, London.

TA R D I E U-B LOT, M.L. , JA EGER, P. & A DAM, J.G. 1 9 7 1 . Le Massif des Monts Loma (Sierra Leone), Fascicule 1 . , V. Pteridophytes filicales. Mem. Inst. Fondam. Afrique Noire 86: 1 1 3- 1 77.

T R YON, R.M. 1 94 1 . A revision of the genus Pteridium. Rhodora 43: 1 -3 1 , 37-70, pi. 650-653. WEST, 0. 1 972. F i re, man and wi ld l ife as a interacing factors l imiting development of climax

vegetation in Rhodesia . Proc. Annual Tall Timber Fire Ecol. Conf 1 1 : 1 21 -1 45. WH ITE, F . 1 965. The savanna wood lands of the Zambezian and Sudanian D omains. An

ecological and phytogeographical comparison. Webbia 19: 651 - 1 68 1 . WHITE, F . 1 968. Zambia Acta. Phytogeogr. Suec. 54: 208-2 1 5.

FE R N GAZ. 1 1 (6) 1 9 7 8

SPORE CHARACTERS OF THE GENUS CHEI LANTHES W I T H PARTICU LAR RE FERENCE TO SOUTHERN AUST R A L I A

H E LE N QU I R K & T . C C H A M B E R S

Botany School Un ivers ity o f Me lbou rne,

Parkv i l l e , V ictor ia , Au stra l ia

ABSTRACT

Spores of five of the species of Cheilan thes found in Austra l ia are examined us ing the scan ning electron microscope . All differ markedly from each other in spore ornamentat ion, and one species, C. tenuifo!ia Sw., shows two dist i nct spore types associated with distinct geograph ical distri but ion patterns. Spores of th e Mediterranean species C. catanensis (Cosent.) H .P . Fuchs are compared with those of C. vel/ea ( R .Br . ) F . Mue l l . of Austra l i a , and found to be very d ifferent from one another.

I N.TRO DUCT I O N

385

The fern gen u s Cheilanthes Sw. is a complex group of appro x i m ately 1 50 species , found th roughout the wor ld, but pr imar i ly i n dry, exposed, rocky a reas. Pre l im inary

study ind icates that 1 1 or 1 2 spec ies are p resent i n Austra l i a , but accu rate taxonomic

del im itat ion of some of these req u i res more deta i led investigat ion .

The h igh degree of i ntraspecif ic var iab i l ity with i n the widespread species C.

tenuifo/ia Sw. and the l esser known and more restricted spec ies of Queensland and

northern Austral i a , present many taxonomic d ifficu lt ies .

The best known Austra l i a n spec ies a re wide ly d istri buted , and at least th ree (C. sieberi Kze., C. distans ( R . B r . ) Mett. and C. tenuifolia ) are a l so found outside Austra l i a .

Vary ing d istr ibut ion patterns from species to species suggests that they d iffer

s ign i ficantly from each other in the i r tolerance to arid ity .

Pich i Sermol l i ( 1 951 ) demonstrated the d istinctness of C. vel/ea , C. /asiophy/la

and C. distans, species wh ich prev ious ly had been confused by a n u m ber of writers .

The d ist inction between C. tenuifo/ia and C. sieberi has a lso been subject to

controversy ; for example , W i l l is ( 1 970) referred to C. sieberi as a var iety of C.

tenuifo/ia but was dou btfu l even of i ts var ietal status .

Previous stud ies of spore morphology i n the genus Chei/anthes have been

reported by Tryon and Tryon ( 1 973 ) , K nobloch , Sp ink and F u l fs ( 1 970) , Dev i , Nayar

and Knobloch ( 1 97 1 ) N ayar and Devi ( 1 967) and Welman ( 1 970) . Spore morphology

of only one Austra l i a n species, C. tenuifo/ia . has prev ious ly been descr ibed .

The present study i s concerned with the exami nation of the spores of f ive of the

species of Cheilanthes found in Austra l i a , i n order to prov ide some addit ional

characters and to determ i ne the ir poss ib l e taxonomic usefu l ness . These species are C.

tenuifolia , C. sieberi, C. distans, C. lasiophy/la Pie . Ser . and C. vel/ea ( R .Br . ) F . Muel l .

MATER I A LS A N D M ETHODS

Spores from both herbar ium and fresh m ateria l were used. The spec i mens studied are l i sted after the descr iption of the spores of each species .

Spores from fresh m ater ia l were o btained by picki ng a few p innu l es which bore r ipe, black sporang i a . These were washed under ru n n i ng water, folded in c lean paper

and l eft for 1 -2 days, after which t ime spores had been shed. Those from herbar ium

speci mens were sel ected from sor i which appeared mature, and i n which a s i gnif icant

n u m ber of the sporangia had a l ready deh i sced . Spores were mounted o n standard

386 F E R N G A Z ETTE: V O L U M E 11 ( PA R T 6) 1 97 8

a lumin ium stubs, either on double-sided st icky tape, or i n a smal l drop of g lue prepared i n acetone from double-sided sticky tape (Chambers and Godwin 1 97 1 ) .

Stubs were coated with carbon, then gold pal l ad ium, wh i l e being rotated i n the vacuum un it on a p lanetary attachment. The specimens were studied on a Cambridge S4- 1 0 scanning electron microscope .

I n order to determine the presence of a perine, the spores were treated with 1 N NaOH, accord ing to the method devised by Erdtman ( 1 960) and modified by Gastony ( 1 974) and as used by Gastony and Tryon ( 1 976) .

CHARACTERISTI CS AND NOMENCLATU R E USED TO DESCR I B E THE SPOR E COAT

Almost every study in recent years of fern spore coat characteristics h as tended to create yet another set of def in it ions, both for the spore coat layers and the spore coat ornamentation . Clearly , a great deal more information, particular ly from deve lopmenta l studies, wi l l be necessary before any rea l ly mea n i ngfu l set of general isations may be made on the true n ature and homologies of these l ayers. For th is reason we h ave chosen to fol l ow the sign ificant recent account of spores of chei l anthoid ferns by Tryon and Tryon ( 1 973) .

The term sporoderm i s used for the spore wal l , when referring to i t genera l ly . The outer l ayer of the sporoderm is regarded as a per ine, and presumably origi nates from the tapetum .

Spores of a l l species studied were treated with 1 N NaOH (fo l l owing Gastony 1 974) . This caused s ignificant swel l i ng and even d isru ption of the outer sporoderm l ayer, and, fol lowing G astony and Try on ( 1 976) , this l ayer is therefore interpreted as perine, and the surface below as ex ine . Fig. 1 shows spores of C. distans, C. tenuifolia and C. sieberi before and after treatment with 1 N NaOH.

a

-··· w· c e

d

F I G U R E 1 a-f. Light micrographs of spores, before and after treatment with 1 N sodium hydroxide, to expand and thereby demonstrate the presence of a perine layer. All x 500. a, b, C distans M E L 51 5005, Dargo, Victoria; c, d, C. tenuifolia M E L 5 1 5001 , You Yangs, Victori a ;

e, f , C. sieberi M E L 5 1 4993, Y o u Yangs, V ictoria.

Q U I R K & CHAMBERS: SPO R E CHA RACTERS I N CH E I LANTHES 387

Perine may be of one or more l ayers, the outer usual ly ornamented, and also often with contours created by the trirad iate scar of the exine showing. The exine is regarded as the layer of the sporoderm immed iately below the per ine. The outer su rface of the exine m ay, in }Ome cases, also be ornamented .

Descriptive terms used by Try on and Try on ( 1 973) are used here to describe the su rfaces of the sporoderm . These are :. smooth, cristate, verrucate, reticulate, echinate and granulose.

R ESULTS

C. tenuifolia

Mapping of col lection local ities of h erbarium specimens has shown that there is a defin ite d isjunction i n the distribution of Cheilanthes tenuifolia between ( i ) southern Austral i a and ( i i ) northern Austra l i a and south-east Asia . There is a corresponding disjunction in spore scu l pturing characteristics of northern and southern specimens (see fig. 2) .

Northern Australian and S E Asian spore type : • C. tenuifolia .a. C .contigua

Southern Australian spore type : • C. tenuifolia

F IGURE 2. Map showing the distributions of the two spore types of C. tenuifo/ia. For the northern Austra l ian and S:E. Asian spore type, distinction is made as to whether spores are from

typical C. tenuifolia specimens or from specimens of C. contigua.

Southern Australia. Spores of plants from southern Austral i a identified as C. tenuifolia are spherica l , or nearly so, 40-50 ,1..1m in diameter, have a cristate perine, and disconnected, i rregu lar ridges forming a tri lete mark (fig. 4 a , b) . The perine i s a disti nct outer layer, which can break off entirely, to reveal the outer surface of the exine with its finely granu lose texture and prominent tr i l ete mark (fig. 4 c, d ) .

a

10cm

IEUI"ot

___ ..

. � �---- _ _,..,.. .. ......... �"·--·- �·-

b

.. " ' . . - � ) f. \• ) .� ... (

\!� �,..._

c

-;.;-FIGUR E 3. Herbarium specimens of C. tenuifolia from southern and northern Australia, and of C. contigua showing longer, less finely divided frond of C. contigua : a. C. ten�ifolia, M E L 5 1 4999, Springhurst, Victoria; b. C. tenuifo!ia, M E L 504703, Bel lenden Ker Range, Queensland;

c. C. contigua, M E L 504704, Port Darwin , Northern Territory .

w CXl CXl

, IT1 ;JJ z G) )> N IT1 -i -i IT1

< 0 r c g IT1 ... ... "0 )> ;JJ -i "' ... <D " CO

Q U I R K & C H A M B E R S : SPO R E CHA R ACTERS I N C H E I LANTHES 389

Northern Australia, South-east Asia and the Pacific. A problem ar ises when considering the northern specimens of C. tenuifolia , because the sporophyte, although often i ndistinguishable from southern spec imens in general appearance (fig. 3 a, b ) , a l so appears, at l east superfic ia l ly , to grade i nto a less f inely div ided form. Th is form has very e longated u l timate p innu les, and in extreme cases may be no more than bipinnate for much of its length (fig. 3 c) . After carefu l exam ination of many specimens of this form , it has been assigned to Cheilanthes contigua Baker, a species with both "frond d iv is ion pattern and scale cover d istinct from those of C. tenuifolia .

F I G U R E 4. Spores of C. tenuifolia in southern Australia : a, C. tenuifolia, M E L 1 4995, Ei ldon , Victoria, spore showing cristate per ine, X 8 1 0; b, su rface deta i l , X 1 940; c, C. tenuifolia, MEL 5047 1 6, Recherche Archipelago, Western Austral ia, whole spore showing exine, X 950, d, Surface

detai l , X 1 940.

However, both the northern Austra l i an and northern extra-Austral i a n materia l of C. tenuifolia and C. contigua h ave identical sporoderm scu lptu ring, and the spores are qu ite d i stinct from those of southern C. tenuifolia . They are d ist inctively triangular in shape, and 40-55 um across . The sporoderm has a prom inent tr i l ete mark and is reticul ate-ech inate, cons isting of ribbed spikes protrud i ng from the f ine ly granu lose surface (fig. 5 a-d ) . These spikes may wear off and the outer sporoderm break away to reveal the smooth inner sporoderm (f ig. 5 e, f ) .

390 F E R N G AZ ETTE: V O L U M E 1 1 P A R T 6 (1978)

F IG UR E 5. Spores of C. tenuifolia and C. contigua in northern Austra l ia and S.E. Asia : a, C. contlgua, BM, Shevaroy Hil ls, Southern I ndia, whole spore showing sporoderm, X 840, b, Surface oetail, X 1 940; c. C. tonuifolia , BM. Luzon, Phi l ippines, whole spore showing sporoderm, X 750, d, Surface detail, X 1 850; e. C. ronuifolia , BM Timor ; whole spore from which spines of sporoderm have worn away, and part has worn off entirely, to reveal the smooth inner sporoderm,

X 820, f , Surface deta i l , X 1 850.

QU I R K & CHAMBERS: SPORE C H A RACT E RS I N C H E I LANTHES 391

Specimens studied:

Southern C. tenuifo/ia spore type:

Collector Location Date Herbarium

R .D. Joyce 6609 Barlee Ra. , Henry R . , W.A. August 1 96 1 P ERTH

A. Morrison E l len 's Pea k, Stirl ing Ra ., W.A. Oct. 1 962 P ERTH

E.N .S. Jackson 1 239 Eucla Division , Esperance Dist., W.A . Sept. 1 968 P ERTH

J.V. Blockley 307 Duck Ck. to Fortescue R . Hammersley Ra. July 1 966 P ERTH

J. Somervi l le Bellerive, Tasmania Nov. 1 940 H02221

A. V. G ibl in 7-Mi le Beach, Tasmania Nov. 1 920 H02230

L. Rodway Schouten Is ., Tasmania April 1 925 H02228

J. Somervi l l e Buckland Tasmania Jan. 1 940 H02224

Aust. Geograph ic Soc. Sandy Hook Is . , Recherche Arch . , W.A. Nov. 1 950 M E L504716

T.C . Chambers Snobb's Ck . Rd. , near E ildon , Vie. Sept. 1 975 M E L5 1 4995

H. Quirk No.20 You Yangs Forest Park, Victoria Apr i l 1 975 M E L51 4996

H. Quirk No.87 You Yangs Forest Park, V ictoria Aug. 1 975 M E L5 1 5000

H. Quirk No.79 You Yangs Forest Park, Victoria April 1 975 M E L51 5001

H. Qu irk No.1 1 2 Big H i l l , south of Bendigo, Victoria Sept. 1 975 M EL51 4998

H. Qu irk No. 1 2 Warby Ra., N . E . Vie. Feb. 1 975 MEL5 1 5003

E. Canning EMC Springhurst, N .E .Vic. May 1 975 M E L51 4999 4014B

T.C . Chambers Mt. Alexandra, Vie. Sept. 1 975 M EL5 1 4997

H. Quirk No .93 Arthur's Seat, Vie Aug 1 975 M E L5 1 5002

Northern C. tenuifolia spore type ( i ) C. tenuifo!ia:

P.R . Messmer West Cairns Ra., Qld. July 1 954 M E L504700

Karsteio Trinity Bay, Qld. 188 1 M E L504701

S. Johnson Bellenden Ker Ra., Qld. 1 891 M E L504703

H.O. Forbes 3445 Fawnaba Hi l ls, Timor 1883 B M

B. Seeman Fiji Is lands 1 860 B M

C.J. Brooks Sarawak, Borneo 1 909 B M

Cuming No.62, 281 Luzon, Phi l ippines 1 84 1 B M

C.J. Simons Khasi Hi l l s , I ndia 1 932 B M

Ha nee Whampoa, China - B M

J. Lamont No. 1 006 West Pt Victoria, Hong Kong 1 873 B M

392 F E R N G A ZETTE : VOLUM E 1 1 PA R T 6 ( 1 978)

Collector Bradshaw & Alien

R.L. Specht

Location Prince Regent R ., West K imberleys, W.A.

South Bay , Bickerton Is., N .T.

Northern C. tenuifolia spore type : ( i i ) C. contigua

Collector Location J.S. Beard 701 7 Mitchell Plateau, N . K imberley , W .A .

C.A. Gardiner Prince Regent R., Ki mberleys W.A.

A.S. George 1 2827 Prince Regent R ., W.A.

Dallachy Rockingham Bay, Old.

Schultz 207 Port Darwin , N .T.

R . Brown 'North Coast' Aust.

L Faucheux Shevaroy Hi l l s Southern I ndia

F.B. Forbes 570 Malaya

Banks & Solander Endeavour R., Old .

c: sieberi

Date 1 891

June 1 948

Date June 1 974

June 1 921

-

-

-

1 802-5

Oct. 1 939

-

1 770

Herbarium M E L50471 9

M E L50471 1

Herbarium P ERTH

P ERTH

P ERTH

M E L504705

M E L504704

B M

B M

B M

B M

.Spores of C. sieberi are spherical , ana e ither 40-50 or 60-75 pm in diameter. The perine i s verrucate - that is, with smal l , low, rounded tubercles over the entire surface. The fine texture of the per ine is granu lose. The surface of the per ine may be clean , except for � few small globules of loose. sporoderm materia l ( fig . 6 a, b ) . or may be coated with a random, open, irregu lar ly br.anched materi a l , presumably of tapetal origin and la id down in the final stages of spore formation just before deh iscence of the sporangium (f ig. 6 c, d) . The exine surface is more f inely verrucate {f ig . 6 e ) .

Almost a l l pl ants exami ned have spores lack ing a tri lete mark, but those from two local ities studied have spores of identical scu lptu ring, but with a conspicuous tri lete mark {fig. 6 f ) .

Specimens studied:

Collector Location Date Herbarium J.W. Stalker Rockhampton, Old. 1876 B M

P. Hynes Wairakei Thermal District. N .Z 1 953 B M

Say er Golden Valley, W.A. 1 888 P ERTH

M. Koch I X Watheroo Rabbit Fence, W.A. 1 905 P ERTH

G . Ch ippendale Todd R , N .T. Nov. 1 954 M E L50471 2

R .A . Saffrey No.435 Pallarup Rocks, S .E . of Lake King, W.A. Aug. 1 968 P ERTH

L. Norton Between the Upper Bogan and the Lachlan M E L504708 Rivers, N .S .W .

Q U I R K & CHAMBERS: SPO R E CHA RACT E RS I N C H E I LA NT H ES 393

F I G U R E 6. Spores of C. sieberi : a, C. sieberi, BM, Wairakei, New Zealand, whole spore showing verrucate perine, X 760, b, surface detai l , X 1 940; c, C. sieberi, M E L 514991 , Wycheproof, Victoria, spore with irregular network overlying verrucae of perine, X 672, d, surface deta i l , X 2000; e , C, sieberi, PERTH, Watheroo, Western Austral ia, spore showing verrucate exine, X 760; f , C. sieberi, M E L 504706, Mudgee, New South Wales, spore with prominent trilete mark, and verrucate perine

and exi ne, X 880.

394 F E R N GAZ ETTE : V O L U M E 1 1 P A R T 6 ( 1 9 7 8 )

F I G U R E 7. Spores of C . distans : a, C . distans, MEL 51 5005. Dargo, Victoria, whole spore with �;�Chinate·retlculate perine, X 780, b, Surface detail , X 1 920; c, C. distans, type specimen , BM, A . Brown 4, Port Jack�on, N e w South Wales, whole spore, X 680; d , C. distans, M E L 50471 0, t;ocopara Reserve, New South Wales, surface detail showing granulose exine X 1 940; e, C. distans, M E L 504713, Clermont Queensland, spore with prominent trilete. mark, X 9 1 0, f, surface detai l , X

1 920.

Q U I RK & CHAMBE RS: SPO R E CHA RACT E RS I N CHEI LANTHES 395

Col lector Location Date Herbarium

Taylor Mudgee, N .S.W. 1 870 M E L504706

R. Thorn Wagga Wagga, N .S.W. March 1 885 M E L504702

H. Quirk No.1 1 1 Big Desert, Vie. Sept. 1 975 M EL5 1 4990

I .G. Stone Wycheproof, Vie. Sept. 1 975 M E L5 1 4991

H. Quirk No. 21 You Yangs Forest Par k , Vie . April 1 975 M E L5 1 4992

H. Qu irk No. 1 9 You Yangs Forest Park, Vie. April 1 975 M E L5 1 4993

I .G . Stone Pyramid H i l l . N .W. Vie . Sept. 1 975 M E L5 1 4994

C. distans

Spores of C. distans are spherical in shape, 40-80 )Jm in d iameter, w ith an ech inate­reticulate perine of groups of 4-5 protuberances coming together to form s ingle spines (fig. 7 a, b). Spores of the type specimen are also of this pattern (fig. 7 c ) . The perine forms a dist inct outer l ayer, cover ing a f ine ly granu lose exine (f ig . 7 d) . Spores of plants from a l l but one local ity lack a tr i lete mark, but those of a specimen from Queensland (ME L5047 1 3) show identical pattern ing of both perine and ex ine, but with a prom inent tr i lete mark (fig . 7 e, f). These were also the smal lest of the spores studied, being only 40-50 )Jm i n d i ameter. Specimens studied:

Collector Location Date Herbarium

R. Brown Port Jackson, N .S .W. 1 802-5 B '111 Type . Specimen

Christensen Laudes, Noumea, New s;aledonia 1 922 B M

C. Andrews Toodyay, W A. Aug. 1 904 PERTH

Ful lager Lord Howe I s - M E L

S . Johnston Clermont, Old. Oct. 1 897 MEL504713

J.H . Wil l i s Cocopara Nature Reserve, N .S.W. Oct. 1 969 M EL50471 0

H. Quirk No.1 Nr. Dargo, Vie. Feb. 1 975 M E L51 5005

C. lasiophylla_

Spores of C. /asiophyl/a are spherica l , 60-70 J-lm in diameter, and have a reticul ate perine of strongly anastomosing muri (f ig. 8 a, b ) . The perine is a dist inct outer l ayer, overly ing a granulose exine (fig. 8 c , d ) . No tri lete mark is present.

Specimens studied:

Collector Location Date Herbarium R. Brown Memory Cove, Eyre Peninsula, S.A. 1 802-5 B M

A.S. George 421 5 Victoria Rocks, S .W. of Coolgardie . W.A. Sept. 1 962 P ERTH

G. Chippendale Mt. Olga, N .T. Sept. 1 956 M E L502446

396 F E R N G A ZETT E : V O L U M E 11 (PA RT 6) 1978

F IGUR E 8. Spores of C. /asiophyl/a: a, C. lasiophylla, BM, Eyre Peninsula, South Austra l ia , whole spore showing reticulate perine, X 680, b, surface detai l , X 1 850; c, C. /asiophylla, M E L 502446, M t . Olga, Northern Territory, spore with perine broken away to reveal granulose exine, X

700, d, su rface detail of exine, X 2000.

Collector Location Date Herbarium

T.S. Henshal l 1 70 Mt. F raser, N .T. Apri l 1 974 M E L504720

J.H. Wi l l is Mt. Liebig, N .T. July 1 966 M E L504709

H. Quirk No.1 07 Big Desert, Vie. Sept. 1 975 M E L5 1 5004

C. vel lea The outer sporoderm of spores of C. vel/ea has a finer and smoother pattern ing tha n that of the other species exam ined (fig. 9 a, b) . The granular outer coat i s often creased on one l i ne, but a tri l ete mark is not present. The outer sporoderm is c losely appressed to the smooth i n ner surface. Spores are c.60 um in d iameter.

Q U I R K & CHAMBERS: SPO R E CHA RACT ERS IN C H E I LANTHES 397

F I G U R E 9 . Spores of C. ve/lea and C. ca tanensis : a, C. velfea, type specimen, B M , R. Brown , 5, Caledon Bay , Northern Territory, whole spore showing granulose perine X 660, b, surface deta i l , X 1 850; c , C. catanensis. BM, Lake Hula, Palestine, spore with verrucate sporoderm , X 760, d ,

Su rface deta i l , X 1 850.

Specimens studied:

Collector Location Date Herbarium

R. Brown Caledon Bay, N T. Feb. 1 803 BM (Type specimen)

W.R . Eaton Calder R . West Kimberly, W .A. Sept. 1 923 P ERTH

E. G i les K imberley District, W .A. 1888 M E L50361 2

Persich Endeavour R . , Old. May 1 887 M E L504718

A member of the genus, C. catanensis (Cosent.) H .P . Fuchs, found in the Mediterranean region, has been confused with C. vel/ea on the grounds of its superficial vegetative morphology, and espec ia l ly its fronds densely covered with wh ite hai rs . Scanning electron microscopy of the spores of th is Mediterranean fern (taken from herbarium specimens at the British Museum - R . F . Jones No. 350, Lake H u la, Palestine, Dec. 1 935; and F.M. Norris E l ijah 's ·Tomb, Bauiges, Syr ia , 1 945) clearly ind icated a marked d i fference from any Austra l ian m ater ia l we have encou ntered (fig.

398 F E RN GAZETT E : V O L U M E 1 1 PART 6 ( 1 978)

9 c, d ) . Spores are c.65 }Jm in diameter and tetrahedra l , with a rounded d i stal surface and flatter proximal surface, a fa int tri lete mark and two deep equatorial s l i ts on either side. They are strongly verrucate, with a f inely granular texture.

D I SC USSI O N

Examination of spore morphology of these Austra l i an species of Cheilanthes strongly supports the existing boundaries betwee.n them, and points to a possibl e new d i vis ion with in the species C. tenuifolia . Al l five have distinct patterns of sporoderm scu l pturing, and each fits i nto one of the general k inds of sporoderm of chei lanthoi d fern described b y Tryon a n d Tryon ( 1 973) .

The citation accompanyi ng the orig inal descri ption of C. tenuifolia i n Swartz ( 1 806) is "I nd ia· Oriental i s"*. Unfortunately we have not se�n spores of the type, but the str ik ing d ifference between the two k inds of spores of C. tenuifolia reported in th is study, and the corresponding separation i n the i r d istr i bution patterns, suggests that the ferns of southern Austral i a thought to be C. tenuifolia may, in fact, be a d ifferent species, or perhaps subspecies. This possib i l i ty points to the need for more cr itical morphological and cytological study of the pl ants themselves. The gradation in degree of d ivision of the fronds in C. tenuifolia in northern areas, and the existence of identical spores in both C. tenuifolia and C. contigua, further emphasises the need for detai led re-exami nation . lt i s poss ible that there may a lso be more than one species in this com plex in northern Austra l i a and south-east Asi a .

Spore m orphology also clearly demonstrates the d istinctness o f the previously confused C. tenuifolia and C. sieberi.

Most of the specimens of C. sieberi have spores which l ack a tri lete m ark, and this reflects their apogamy. .

Cyto logical investigation of Austra l i an material has shown that the sporophyte of C. sieberi i s a triploid of n = c.84, and that only 1 6 spores are formed, by m itosis, in the sporangiu m . Brown l ie ( 1 957) has reported a s i m i lar chromosome number for New Zealand populations.

Most ·specimens of C. distans also h ave spores wh ich l ack a tr i lete mark, and they too are formed by mitosis . The existence with in these two species of some p lants with wel l formed spores of identical scul ptur ing, but which do show a prominent tri lete mark, suggests that these may be a l lopo lyRioids not separable on gross morphological characters, but capable of meios is, and poss ibl y of sexual reproduction.

The reticul ate structure of the sporoderm of C. lasiophylla varies i n its degrE:e of complexity, but is clearly distingu ishable from the smooth, granulosa sporoderm of C. vel/ea , with which species it has often prev iously been conf�;�sed . �- lasiophyl/a i s apogamous, and the absence o f a tri lete mark i n spores o f C. vel/ea suggests that it, too, reproduces apogamously.

Th is study has a lso demonstrated the d istinction between spores of C. catanensis and C. vel/ea; their differences suggest that they are probably only d i stantly rel ated.

Spore characteristics clearly offer an important tool for the taxonomic del i neation of species of Cheilanthes in Austra l i a . These spore characters lend weight to existing species boundaries, and a lso point to exciting new areas of research on poss i ble intraspecific boundaries not d iscern ib le from gross morphological study.

ACKNOW L E DG E M E NTS

We wish to thank the fol l owing for mak ing herbar ium specimens available to us, and for a l lowing spore samples to be taken from them : Mr A.C. Jermy and Mr J.A. * Swartz, Syn . F i l . p. 332: Habitat in I ndia orienta l i : China: I ns . phil ippinis

·.

Q U I R K & CHAMBERS: SPO R E CHA RACT E R S I N C H E I LANTH ES 399

Crabbe of the Department of Botany, British M useum (Natural H istory ) , London ; Dr D . M . Church i l l and Mr T.B. Mu i r of the National Herbariu m , Royal Botan ic Gardens, Me lbourne ; Mr J. Parham of the Botany Department, Un ivers ity of Tasma n i a ; Mr J . Green of the Western Austral i an Herbarium, Perth . W e are especia l ly indebted to Messrs Jermy and Crabbe for the ir i nterest and su pport in th is project.

This study was done with the assistance of a Melbourne Un iversity Postgraduate Scholarsh ip to one of us ( H . M .G. ) .

R E F ERENCES BROWN LI E, G . 1 957. Cyto·taxonomic studies of New Zealand Pteridaceae. New Phytol. 56:

207·209. CHAMBERS, T .C. & H. GODWIN. 1 97 1 . Scan ning electron microscopy of Tilia pol len . New

Phytol. 70: 687-692. DEVI , S., B.K. NAYAR & I .W. KNOBLOC H . 1 971 . Spore morphology of some species of

Cheilanthes and Notholaena. Grana 1 1 : 27-35. DOM I N , K . 1 91 5. Beitriige zur Flora und Pflanzengeographic Australiens I, 1 & 2. Pteridophyta,

Gymnospermae, Monocotyledoneae. Bib/. Bot. 20.

ER DTMAN, G . 1 960. The acetolysis mettiod. A revised desc ription . Svensk. Bot. Tidskr. 54: 561 -564.

GASTONY, G .J . 1 974. Spore morphology in the Cyatheaceae. I . The perine and sporangia! capacity : general considerations. Am. J. Bot. 6 1 : 672-680.

GASTONY, G .J . & R.M. TRYON. 1 976 . Spore morphology in the Cyatheaceae. 1 1 . The genera Lophosoria, Metaxya, Sphaeropteris, Alsophila and Nephelea. Am. J. Bot. 63 : 738-758.

KNOBLOCH, I .W., G .C. SP INK & J.C. F U LFS. 1 970. Pre l iminary scanning electron microscope observations on the rel ief of the spore wall of some cheilanthoid ferns. Grana 1 1 : 23-26.

NAYAR, B.K. & S. DEVI . 1 967. Spore morphology of the Pteridaceae, 1 1 . The Gymnograrr1moid ferns. Grana Palynol. 7: 568-600.

P ICH I SERMO LLI , R .E.G. 1 957. Notes on some Australian ferns. Webbia 8: 205-2 1 1 . SWARTZ, 0 . 1 806. Synopsis filium . Kilia. TRYON, R .M . & A.F. TR YON . 1 973. Geography, spores and evolu tionary relationships in the

chellan thoid ferns. In : A.C. Jermy & J .A . Crebbe (Eds.) The Phylogeny and Classification of the Ferns: 1 4 5· 1 54. Supp . No. 1 J. Linn. Soc. (Bo t.) 67: 1 45-1 53.

WE LMA N , W.G. 1 970. The South African fern spores. In: E .M . van Zinderen Ba k ker (Ed. l South African Pollen GFains and Spores, VI. Cape Town, Bal kema

REVIEW

A L TAS OF FERNS OF THE BRITISH ISLES by A. C. Jermy, H.R. Arnold, Lynne Farrell & F.H. Perring. 101 pp 2 1 x 29.5 cm. Published jointly by The Botanical Society of the British Isles and The British Pteridological Society, London, 1978. Available from F. & M. Perring, Oundle Lodge, Oundle, Peterborough PE8 5TN, England. Price (paperback) £3.50 (including postage).

Th is book i s a tri bute to British botan ists, and especia l ly to British pterido logists, and as much to amateurs as to professiona l s . For there can be few who have had an interest in British pteridophytes in the f ield who have n ot in some smal l way contributed to the information conta i ned with in it. Some ( not mentioned in the authorsh ip) , who have been regular participants of f ie ld meetings and co l l ected very many of the records, have certa in ly contri buted much.

This Atlas attempts to co l l ate and present in map form a l l the many changes in our knowledge of pter idophyte occurrence in the British f lora that have developed since (and been stimulated by ? ) the pu bl icat ion of the original Atlas of the British Flora, now 1 6 years ago. In th is it certa in ly succeeds.

The present known ranges are g iven for SO pteridophyte species or subspeices ( includ ing 24 fern a l l ies) and 29 hybrids ( inc luding 7 fern a l l ies) in 95 clear, large

400 F E R N GAZETTE: VOLUME 1 1 P A R T S ( 1 978)

format ( 1 7.5 x 1 9.5 cm . ) , black and white dot maps. The maps appear one per page, and their large s ize makes them eas i ly inspected in detai l Species are recorded on the now-fami l iar 1 0-km British grid squares used for the original A tlas of the British Flor{!.

Readers m ight l i ke to annotate their copies of the new Atlas to note, however, that in general open circles in the new Atlas indicate pre- 1950 records and sol id dots post- 1950 records (not pre and post 1 930 as in the old Atlas of the British "p fora), for mention of this point has been inadvertently omitted. As yet there are no transparent overlays provided to the new map scale (the ones from the old Atlas no longer t it ) . although to do t h i s would presumably have i ncreased the price (perhaps these cou ld be made avai lable separately at a later date?) . A helpfu l point is, however, that th is pteridophyte-only volume, does have i ts own index, which i s necessary to quickly locate species amongst the surpri s ingly large number of pages.

The maps are accompanied by textua l comments on the taxa by A.C. Jermy. These i nclude reference to some of the more signif icant taxonomic or ecological poi nts about the plants concerned, although are not, and are probably not i ntended to be, com plete synopses or· b ibl iograph ies for each. More extensive accounts are given for the identification of Asplenium trichomanes i n Britain and for the species of the Dryopteris filix-mas complex.

For the sheer amou nt of manpower that has gone into the m ak i ng of this volume, a h igh standard of presentation m ight be expected. This seems l argely ach ieved. Doubtless small errors of fact or omission have been included, however, which wi l l become apparent through usage, and if these are notified to the Biological Records Centre they can presumably be corrected in a future edition . One error that readers might l i ke to· correct in their own copies, however, is the spel l ing throughout p.95 (also mentions on p.87 and i ndex ) of "Dryopteris x ambrosiae" to its correct spel l ing as Dryopteris x ambroseae, a s this was not intended, I understand, to be a proposal for an orthographic change.

The i nclusion of maps of cr itical taxa (especial ly hybrids) shows how widely some of these are now becoming recogn ised in the British I sles. lt seems l i kely that severa l of these remain yet cons iderably under-recorded : particu lar ly perhaps Po/ypodium interjectum, the subspecies of Asplenium trichomanes, Dryopteris x tavelii, D. x dpweveri, Equisetum x litora/e, Po/ypodium x maf1toniae a nd possib ly Asplenium onopteris and hybrid Polystichum. Here there is clearly room for more work to be done.

Pteridophytes, in tfle nature of th ings, tend to appear amongst the f irst in such projects as these maps, and hence tend to be ahead of other grou ps and thus set trends and standards to be fol lowed . The com pletion of th is usefu l volume now begs the question : where do we go in Brit ish plant recording from here? Some suggest mapping

. on a f iner grid scale. I wou ld prefer to suggest that pteridology wil l need to harness the enthusiasm and abi l i ty that this Atlas h as shown to be present amongst B.P .S. a nd B .S.B. I . members for the collection of much more -thorough ecological data on pteridophytes .· throughout their ranges in the Br itish I sles. Such information, once gathered, - the "how" and "why" of p lant d istr ibutions and not just the "where" -wi l l become even more i mportant as pressures on conservation and land u se increase.

I n the meantime, the present Atlas w i l l clearly stand as a pteridological m i lestone, and a val u able foundation on which developing further record i ng can be based. Botan ists wil l probably find that l i ke me, they real ly need two copies of th is useful volume - one for the bookshelf �nd one for the car !

C.N. PAG E

F E R N G A Z . 1 1 ( 6 ) 1 9 7 8

PRE L I M I NARY NOTE ON A FOSSI L EQU I SETU M F ROM COSTA R ICA

L . D . G O M E Z

H e r ba t· i o N ac i o n a l , M u seo N a c i o n a l de Costa R ica , San Jose , Costa R ica.

A BSTR ACT

A brief description of two secti o n s from t h e aerial shoots of an u n known species of

Equisetum subg. Hippochaete f o u n d in travert i n e deposits ot Upper Tert i a ry of

Costa R ica i s prese n te d .

I N T R O D U C T I O N

401

I n the pa laeobota n ica l l iterature there a re n u merous record s of foss i l Sphenophyta

wh ich h ave been tradit i ona l l y pl aced i nto five orders : H ye n i a l es , Pse u d o born i a l es ,

Spb e n ophy l l a l es , C a l a m ita les and Equ iseta les (Arno l d 1947, H i rm e r 1 92 7, Sm ith

1955) the l atter com p r i s i ng the one fam i l y Equ i setaceae which d iffers from a l l other

sphenophytes i n the l ac k of secondary growth , h a v i n g sm a l ler l eaves and no ste r i l e

bracts i n t h e stro b i l u s . The fam i ly inc l u des two genera : Equisetites Ste r n b . t h e o l dest

known m e m be r descri bed from the R h aetic of Germany and ran g i n g from Devon i a n to

Tert i a r y , w i th sever<:� l records for the U n ited States , Mex i co , Peru, B r a z i l a n d A rgent i n a

( Reed , 1971 ) . T h e other g e n u s i s Equisetum wh ose foss i l record exte n d s from the

Caenozoic to the Recent and i s the o n l y e xta n t genus of this old fam i l y o f vascu l a r

plants. Jongmans ( 1 922) l isted 1 43 fossi l species ascr ibed t o Equisetum a n d for the

F I G U R E 1 . Travert ine s l a b and i mprints of two stems of the Costa R ica foss i l Equisetum s p .

( sc a l e in c m . )

402 F E R N G A Z ETTE: V O L U M E 1 1 PA R T 6 { 1 978)

F IG U R E 2. Close-up of imprint of fossil Equ isetum showing ridges and nodal sheath.

subgenus Hippochaete the fossi l evidence is enumerated by Hauke ( 1 963) . There are no records of fossil Equ iseta for Central America.

TH E COSTA R I CA FOSS I L

Recently, a fragment o f a slab of a concr�tionary l im estone of the type known as Travertine or Spring Tuft from the quarries of the R iver Navarro, Province of Cartago, Costa R ica, was found to contain the moulds of two stems undoubtedl y belonging to Equisetum . The impressions are of one node and an internode and show wel l -defined, longitudina l ridges and part of the whorl of scale-l i ke leaves that make the nodal sheath (figs. 1 ,2 ) . The impressions are qu i te rounded, suggest ing a s low and gentle deposition o f the calcareous particles suspended i n water wh ich enabled the matrix to concresce without crush ing and flatten ing the brittle aerial shoots of the horsetai l . Thus, it may be safely assumed that both moulds include more than half of the circu mference of each of the stems and that their d iameter, number of ridges and nodal sheath leaves can be estimated for the l iv ing plants. Acetate peels after cleansing with 1 % aqueous solution of HC I reveal noth i ng of the epidermal features, the finer part icles of the embedding carbonates having f i l l ed the sunken stomatal apparatus and obl ite rated the cuticu lar interstices a long cel l u l a r wal ls . A s i l icone cast was obta ined to cou nt the number or ridges as wel l as to determine their configuration (convex, bitu bercu late, etc) and the possi ble pattern of the s i l ica incrustations along them.

The stems are 1 . 6 cm in diameter, had t 32 s l ightly convex ridges, 1 .2· 1 .4 m m w ide. Length of internode was underfermi ned. The nodal sheath was 1. 7-2 cm long and had also :t 32 leaves, the apical teeth or segments were :!: 4 mm l ong. From the meristic in formation at hand it is possible to ascribe this material to the giant horseta l l s of

GOMEZ: FOSS I L EQU ISETUM I N COSTA R I CA 403

su bgenus H ippochaete represented in Costa R ica by E. giganteum L. , E. myriochaetum Cham & Sch lecht. , and their putative hybrid E. x schaffneri (M i lde) Hauke. Nevertheless, the lack of data on the number of rows of sunken stomata , the s i l ica incrustation pattern of the ridges etc. makes assignment to one of the c ited species d ifficu l t and must await the discovery of more material in better preservation .

The region of the eastern Central Va l l ey of Costa R ica where the fossi l comes from is genera l ly considered as an und ifferentiated M iocene·Pi iocene local ity on the evi dence of nearby cl astic and paracl it ic marine sed iments. The travertine quarries of the R iver Navarro are su rrou nded by lava fl ows of Upper Tertiary age and the tuft bears numerous i mprints of angiosperm fo l i age and stems representing Melastomataceae, Lauraceae and Annonaceae. To date, this i s the on ly report of a vascular cryptogam from these calcareous deposits and the f irst record of a fossi l Equisetum for Central America.

R E F ER ENCES ARNOLD, C.A. 1 947. An introduction to Paleobotany. McGraw-H i l l , New York 43 1 pp. HAU K E, R . 1 963. A taxonomic monograph of the genus Equisetum subgenus H ippochaete. Beih.

Nova Hedwigia 8 : 1 23 pp. H I R M E R , M . 1 927. Handbuch der Pal'iJObotanik: Thallophyta, Bryophyta, Pteridophyta. Munchen

and Ber l in , 708 pp. JONGMANS, W .J . 1 922. Equisetales I V. Fossilium Catalogus./1. P/antae. W. Junk , Berl i n , 9 :

51 5-742. REED, C .F . 1 971 . Index to Equ isetophyta . l . Fossiles. Con tr. Reed Herbarium 19: 1 -402. SM ITH, G . 1 955. Cryptogamic Botany. Second ed it ion, McGraw-H i l l Kogakusha, Tokyo, vol . 2:

251 -263.

REVI EW TRA I T£ DE PA LEOBO TANIOUE, by E. Boureau, S. Jovet-Ast, O.A. Hoeg, & W.G. Chaloner. Vol. 2: Bryophyta, Psilophyta, Lycophyta. 845 pp. Price NF580. 00 (about £69.05). Vol. 3: Sphenophyta, Noeggerathiophyta. 544 pp. Price NF400.00 (about £47.62). Vol. 4(1) : Filicophyta. 519 pp. Price NF365.00 (about 43.45). Vol. 4(2) : Pteridophyta. Part 1. 768 pp. Price NF850. 00 (about £ 101. 19). Masson et Cie. Paris.

Foss i l ferns and fern-al l ies are often on ly of pass ing interest to people interested in l iv ing plants. This i s part ia l ly due to d ifficu lties encountered when one attempts to search the l iterature. The l arger texts are often out of date, and the modern scientific papers have been publ ished in a w ide range of journals not norma l ly used by people studying extant materiaL This series, however, goes a long way towards fi l l ing this ga p in the l iterature by compi l ing an a lmost complete catalogue of foss i l pter idophytes. Anyone i nterested i n the past h istory of ferns and their a l l ies wi l l f ind these books of immense value. They are the only parts yet pu bl ished of a series planned to encompass all fossil plants . Various specia l ist authors have a l l succeeded in g iv ing com prehensive com pi lations wh ich shou ld provide the basis for many years of futu re research . Vol u me 2 deals with the psi lophytes and lycopods and a l so includes the bryophytes; Vo lume 3 the horsetai l s and their relations; whi le Volume 4 is devoted to the ferns. They are beautifu l ly produced and lavishly i l lu strated with excel lent photographs, enab l ing one to simply browse. The series is obviously produced for the specia l i st and the ir price wil l effectively stop any casual purchase. Research workers w i l l def in ite ly need access to them but non -specia l i sts should see a copy if at a l l poss ib le . Vo lume 4 part 3 is eagerly awa ited , for it w i l l comp lete the ferns and it is promised to conta in ideas of fern evo lution .

B .A . THOMAS Goldsmiths' College, London.

404 F E R N GAZETTE: V O L U M E 1 1 PART 6 ( 1 978)

THE SOUTHERN FERN GUIDE: SOUTHEASTERN AND SOUTH-MIDLAND UNITED STA TES, by Edgar T. Wherry, illustrated by Jame C. W. Chen and Keith C. Y. Chen. Edition one, reprinted with corrections by John T. Mickel, 1978. Doubleday/A FS 1 17 x 1 10 mm. Price S4.50

Most readers of the Gazette wil l know of th is usefu l companion vol u me to Prof . Wherry's Fern Guide to NE and Midland U.S. and adjacent Canada, first pu bl ished i n 1 964 in the Doubleday Nature Gu ide Series. l t h as now been reprinted b y the New York Chapter of the American Fern Society and is ava i lable from them, care-of the New York Botan ical Garden, Bronx, New York, 1 0458.

This edition is photo-copied and the corrections and additions are confined to one page (p.8) . Most are corrections to n omenclature but Thelypteris thelypteroides M ichx ( 1 803) which shou ld replace T. palustris Schott., ( 1 834) (pp: 44 and 1 02) has not been included . This i s a case where the ear l ier name must be used however much the later one i s loved and used . The f irst correction transfers Hypolepis from Dennstaedtiaceae to Hypolepidaceae "to join Pteridium. ' This is in order but Wherry put the latter genus in "Pteridaceae" and th is should have been corrected . lt is said Hymenophy/lum tunbrigense (wrongly spelt i n the original and correction as tunbridgense) i s now found e l sewhere. The range, if not the exact locat ion cou ld perhaps have been given. Likewise we are to ld to add Trichomanes holopterum Kunze (p. 232) and Lygodium microphyl/um R. B r (p. 238) but no local i ties are g iven.

This l ittl e book, not only broadens our knowledge of warm temperate ferns, it a lso has many facets of knowledge e.g . on the cu I tu re of each species, epithets and thei r significance, autl)ors of fern Iat in name etc. I f you do not have it a l ready you shou ld take the chance of getting i t now it is aga in ava i lable.

A.C. J E R M Y

F E R N GAZ . 1 1 (6) 1 9 7 8

SPORODERM ARCHITECTURE I N MODERN AZOLLA

K. FOW L E R and J . STENN ETT-WI L LSON Department of Bio logical Sciences, Portsmouth Polytechn ic,

K ing Henry I Street, Portsmouth P0 1 2DY, Hants .

ABSTRACT

The morphology of the megaspore apparatus in extant Azolla is reconsidered and certain terms clarified. Examination of the sporoderm, by means of scanning electron microscopy and thin sectioning of A. pinnata, A. nilotica, A. microphylla and A. filiculoides, indicates the occurrence of five distinct morphological types, though the 3-layered sporoderm is common to all species studied . Sporoderm structure in A. filiculoides var. rubra suggests that this variety may be considered as a d istinct species.

I NTRODUCT I O N

405

Metten ius ( 1 847) described the morphology of the megaspore apparatus with in the section Azo l l a , but it was Strasburger ( 1 873) who provided the fi rst i l l u strations of sporoderm sculpture and structure in A. pinnata, A. nilotica, A. microphylla (described as A. caroliniana by Strasburger) and A. filiculoides. Svenson ( 1 944) considered sporoderm features to be of taxonomic importance, but excluded sporoderm structure in his study of the New World species. More recent contributions on the sporoderm in modern Azolla are : - A. pinnata ( Kempf 1 969a , Sweet and H i l ls 1 97 1 , Mart in 1 976) , A. nilotica (Demal sy 1 954, Martin 1 976) , A. filicu/oides (Bonnet 1 957 , Berte l sen 1 972, Mart in 1 976) . Much of the developmental organ i sation of the megaspore apparatus, particu larly sporoderm d ifferentiation, is sti l l poorly u nderstood.

In recent years, the attention focused on foss i l species of Azolla has undoubted ly provided more information on architecture of the megaspore apparatus than that obtained from modern species. Kempf ( 1 969a, 1 969b) , not on ly provided the basis of our understanding of the morphology of the megaspore apparatus, but a lso demonstrated that interspecific variabi l ity of sporoderm structure provides a usefu l means of taxonomic separat ion and identification of both foss i l and modern species.

The purpose of the present work is to provide pre l i m i nary i l lustrated descriptions of the sporoderm in A. pinnata, A. nilotica, A. microphylla and A. filicu/oides. A more extensive comparative treatment of sporoderm arch itecture i n modern species of Azolla, includ ing sporoderm elaboration a t the proximal surface and its relationship to taxonomy with i n the genus, w i l l be descri bed e lsewhere; as wi l l the signif icance of the sporoderm in the evolutionary development of the megaspore apparatus ( Fowler and Stennett-W i l lson, in press) .

MATER I A LS AND M ET HODS

Herbarium materia l i nvestigated was obtained from the British Museum ( Nat. H ist.) and the Royal Botan ic Gardens, Kew. Spec imens were examined and photographed with a Cambridge I n struments Company Stereoscan . Th in sections, approximate thickness 1 .5 f-l m. were cut with a LKB U ltratome I l l and gl ass kn ife , examined and photographed with a Wi ld-Heerbrugg M20 l ight m icroscope with Photoautomat. Measu rements given are based on median longitudina l sections taken from two to three specimens of each species i nvestigated .

Figured material has been deposited in herb B M .

s up rafi lo s um

\ float

'llii!l J colume l l a col lar

fV- flange #':. groove

e xope rine §.rr- en�operine e x� ne

b

:4---------- pe rin al e xcre s cence

exoperine 2

exope rine 1

F I G UR E 1 . a, diagrammatic median l.S. through megaspore apparatus of a member of section Azolla, showing its organisation and terminology used; b, diagrammatic representation of sporoderm structure of A. filiculoides var. rubra, with terminology used .

""" 0 m

"Tl n1 :0 2 G) )> N n1 ., ., n1 < 0 r c s: n1

"0 )> :0 ., "' ... I!) ...., 2:

FOWLER & STE N N ETT-W I LLSON : SPO RO D E R M A RCH ITECT U R E I N AZO LLA 407

T E R M I N O LOGY

l t is hoped that the fol lowing l ist of terms ( i l l u strated in fig. 1 ) may form the basis for a standardised, s impl ified term inology, at the same time offer ing some clar ification of certa in terms. Though re-defined in some cases, many of the terms have been used by previous authors (Sweet and Chandrasekharam 1 973, Sweet and H i l ls 1 976) .

Megaspore apparatus: essentially a thick-wal led megaspore from which hairs arise to enmesh the floats. The proximal sporoderm often becomes elaborated to form a collar and columel la, the hairs originating in this region forming a superstructure accommodating the proximally positioned floats.

Megaspore: consists of the megaspore proper bounded by the exine, surrounded by the scu lptured hairy perine .

Collar: delimits periphery of the proximal surface of megaspore, appearing raised and contoured due to increased thickness and vacuolation of the endoperine. In extant members of section Azo/la it is tricuspid , with cusps extending between and supporting the floats, and with a downwardly directed flange on the outer face.

Columella (syn. gula, acrolamel l a , labrum, colu mn ) : con ica l , triseptate, centra l ly placed elaboration of the proximal sporoderm composed mai n l y of vacuolate endoperine. The septa ilivide the proximal su rface i nto three equal sectors, and partial ly support the floats. Previous confusion over this term has surrounded its use for both the triseptate structure and the superstructure of hairs on the proximal surface. As interpreted here, the term does not include the hairs.

Filosum: hairs on the sporoderm. The defin ition given by Sweet and Chandrasekharimi ( 1 973) can be applied to a megaspore apparatus showing l ittle polarity . With distinct polarity, it is necessary to distinguish between the proximal ha iry superstructure and the hairs on the remaining megaspore surface.

lnfrafilosum (new term ) : hairs originating outside the col lar region, forming a mat on the perine surface.

Suprafi losum (new term) : proxima l ly positioned superstructure of hairs arising from the col lar region and columel la , and which houses the floats. Basica l ly cy l indrical , but apical ly inverted to become umbrel la-shaped. On removal of the megaspore apparatus from the megasporocarp, the suprafilosum becomes erect and funnel-shaped ( f ig.2al. This basic structure is further modified by float development, resu lt ing in a triseptate form between the f loats.

Apical membrane: remnant of megasporangial wal l attached to apex of suprafi losu m .

Float: vacuolate, pseudoce l lu la r structure often with hairs o n inner faces a n d a t apex which serve as a means of attachment to the suprafi losu m .

Sporoderm : megaspore wal l , consist ing o f innermost exine and 2-layered per ine.

Exine: wal l surrounding megaspore proper. A th in basement layer, the endoexine, may often be del im ited from a thicker, rad ia l ly striated exoexine.

Perine: 2-layered wal l outside exine which gives r ise to the fi losu m .

Endoperine: innermost homogeneous or vacuolate layer o f t h e perine located adjacent, and loosely attached, to the exine. Extensive development of this layer is significant in the formation of collar, columella and sculptural features.

Exoperine: outermost sculptured layer of perine with 2 - 3 zones usua l ly recognisable, excluding the fi losum .

Perinal excrescence: large protuberance from perine surface composed of both exoperine and endoperine.

Use of the terms exine and perine is becoming increasingly acceptable to describe the sporoderm of both foss i l and modern spec ies of Azol/a ( Fowler 1 975, Sweet and H i l l s 1 97 6, Mart in 1 976). Erdtma n ( 1 952) defines the perine as an extra-ex lnous. layer formed by the activ ity of a tapetal plasmodium. Though u se of these terms for Azolla imp I ies a knowledge of sporoderm development wh ich does not ex ist, its use seems justified in v iew of the structural s im i l arity between f loats and massu lae , usua l ly accepted as perinous, and the endoperine.

408 F E R N G A Z ETT E : VO L U M E 1 1 PA RT 6 ( 1 978)

a

9 h

F I G U R E 2. a-c, A. pinnata (Mooney 2 1 83, Borigaon, Kalahandi State, Orissa, India ( K )), a, megaspore apparatus, x 80, b, filamentous excrescence below col lar, x 500, c, exoperine surface showing large excrescences, x 800; d-f. A. nilotica ( Robinson 1 66 1 , L . R ukwa, Tanganyika, Africa, (BM) l. d, megaspore apparatus, x 1 20, e, exoperine surface showing excrescences, x 800, I. foveae w ith exoperinous intrusions, x 800; g-h, sporoderm structure, including excrescences, x 1 500, g,

A. pinnata, h , A. nilotica.

FOWLER & STEN N ETT-W I LLSON : SPO RO D E R M A RC H I T ECTU R E I N AZO LLA

SPO R O D E R M ARC H I T ECTU R E

Section R H I ZOSP E R MA - megaspore apparatus 9-floated.

A. pinnata

409

Sculpture: Distinct ornamentation of large, cy l i ndrical , elongated prostrate perinal excrescences forming the exoperine 3 zone (fig. 2a) . Excrescences immediately beneath col lar are fi lamentous, atta in ing 75.0 pm length but of un iform diameter ea. 5.0 um (fig. 2b) . More prominent excrescences occur on the remain ing sporoderm, be ing larger (diameter ea . 1 5 .0 um, length ca . 1 6 - 40.0 u m ) , with constrictions at irregular intervals, and fused directly, o r by elongated baculae, to the su rface below (fig . 2c ) . The exoperine 2, constititing most of the perine surface, is composed of anastomosi ng bacu lae of un iform diameter ea. 2 .0 pm, with rounded free ends at, or near, the surface. Sporoderm devoid of hai r-l i ke f i laments except in the collar region and on the proximal surface.

Structure (fig. 2g) : Sporoderm thickness ea. 32.0 um including perinal exc rescences which can atta in ea. 1 5 .0 um in height. Exine (ea . 3 .8 ).Jm ) characterised (as in all extant species examined) by radial striations and thin basement zone. Endoperine (ea. 6.8 ).J m ) h omogeneous, composed of elements smal ler than those of the exine. Exoperine 1 (<0.5 ).Jm) composed of both large and small baculae, represents the transitional zone at the base of the exoperine :2 layer. The anastomosing baculae of the exoperine 2 layer (ea. 5.5 J.Jm) occur throughout its thickness. Occasional en larged hollow baculae connect the endoperine with overlying excrescences, and sections clearly indicate that endoperinous materia l , as well as exoperinous, is involved in the composition of these structures.

A. ni/otica

Sculpture: Numerous large spiny perinal exc rescences occur dista l ly ( length usual ly ea. 1 6.0 )Jm, though some atta in 40.0 ).J m ) , often with a recu rved and b lunt apex (f ig . 2d) . Perine surface otherwise foveolate with regularly arranged foveae (ea. 2.0 )Jm in diameter, 4 - 5.0 flm apart) situated in depressions demarcating areas between fused ·claval) of the exoperine. Spines are compound, appearing to be formed by fusion of prolongations of adjacent clavae. Perine surface , including spines, finely granulate (fi g . 2e ) . Intrusion of exoperinous material into foveae from below appears to be a secondary feature in wall development (fig. 2f ) . This feature may have formed the basis for the term 'inperinal prolongation ' (Sweet and Chandrasekharam 1 973) , though there is no evidence supporting the view that such structu res are endoperinous, as suggested by those authors. No hair-l i ke fi laments present.

Structure (fig. 2h) : Sporoderm thickness ea. 29.0 )Jm including perinal excrescences. A coarsely granular endoperine (ea. 3 .0 ).J m ) surrounds the exine (ea. 4.5 •Jm) . Base of exoperine forms a zone of short tapering colu mellae, here designated the exoperine 1 (ea. 1 .0 )Jm ) . Exoperine 2 (ea. 4.8 jJm) forms the general perine surface and is composed of a dense layer of fused clavae with intervening foveae . The exoperine 3 zone consists of perinal exc rescences into which the endoperine extends, as in A. pinnata.

Section AZO L LA - megaspore apparatus 3-fl oated .

A. microphyl/a

Sculpture: Rugulate-verrucate with irregularly arranged foveae of varying size. Numerous hair-l i ke f i laments (diameter ea. 0.5 - 1 .0 1Jm ) often emerge from smal ler foveae (diameter ea. 2 - 5.0)Jm) (fig. 3b) Large rounded foveae (diameter ea. 6 - 8.0 um) impart a distinctly pitted appearance at a low ma_(Jn i fication, the largest cavi ties occu ring toward the distal surface {fig. 3a ) .

Structure (fig. 3c ) : Sporoderm thickness e a . 22.0 ).J m , excluding infraf i losu m . Exine ea. 4 . 2 um. Endoperine (ea . 3 .8 )J m ) coarsel y granular with a low degree of vacuolation . Transition from endoperine to exoperine gradua l , with fusion and thickening of elements toward the upper endoperine su rface, pass ing into an anastomosing network of predominantly tangential ly arranged baculae (diameter ea . 0.5 )J m ) in the exoperine 1 zone (ea. 3 .0 J.J m ) . Exoperine 2 (ea. 1 1 .0 }Jm) with bacu lae extending upward, branch ing and fusing at the ir apices to support a thick, loosely arranged, perforated 'tectum-l i ke ' layer, forming the rugulate-verrucate su rface sculpture. Hairs appear to arise from the exoperine 1 zone.

A. filiculoides

Sculpture: Raised angul;;�r areas interconnected by narrow ridges surround cl osely placed rounded

4 1 0 F E R N GAZETTE : VOLUME 1 1 PART 6 ( 1 97 8 )

g h

F I G U R E 3. a--c, A. microphylla (Molina 3962, En el R io , Ori l l as de l Rio Lizapa, Llano Lizapa, Honduras (BM) ) , a , megaspore apparatus, x 1 1 0 , b, exoperine surface, x 800, c, sporoderm structure, x 1 500; d, e, g , h . A. filiculoides var . rubra, ( Byrne 831 0, Oura Road, Wagga Wagga, N.S.W., Australia (BM) ) , d, megaspore apparatus, x 1 1 0, e, exoperine surface, x 800, g, sporoderm structure at eruption, x 1 500, h, sporoderm structure in depression, x 1 500; f, sporoderm structure

of A. filiculoides, x 1 1 00 (collected by authors from G reywel l , England ) .

FOWLER & ST ENN ETT-W I L LSON : SPO R O D E R M A R C H I T ECT U R E I N AZO LLA 4 1 1

depress ions un iformly distri buted over the perine su rface (f ig . 3d ) . Raised areas prominently ornamented with anastomosing baculae in lateral con tinuity with the relatively smooth , though u�dulatin g, exope rine surface of the adjoin ing depressions. Hair-l i ke fi l aments (diameter ea. 0.5 -1 .0 um) originate beneath the angu lar areas, emerging between the baculate el ements (fi g . 3e ) . A less pronounced rugulate-verrucate scuipture, pierced by foveae th.rough which hairs penetrate, may be seen in certa in areas, possibly representing a l ater deve l opmental stage of the sporoderm .

The above description can be appl ied both to A. fi!iculoides and A. filiculoides var. rubra.

A. filiculoides var . rubra

Structure (f ig. 3f ) : Sporoderm thic kness varies from ea . 1 5 .0 )Jm beneath depressi ons to ea. 42.0 J.lm in raised areas. Raised areas are l a rge interconnecting excrescences formed by eruptions of the vacuolate endoperine and su perposed by exoperine. Below depressions, sporoderm composed of exine (ea. 3 .0 )J m ) , endoperine (ea. 3.0 p m ) , exoperine 1 (0.5 - 1 .0 )Jm ) and exoperine 2 (ea . 8.0 )Jm) . Within an excrescence, endoperine can attain a thickness of ea. 37.0 }J m , exoperine to the outside being reduced to ea. 2.0 )J m . Endoperine granular, with occasional smn l l , centra l ly positioned , rounded alveolae except in excrescences which are composed al most entirely of large rounded alveolae, some exceeding 20.0 )Jm in di ameter. Exoperine 1 composed of short col umel lae. Exoperine 2 forms a thick dense l ayer beneath depressions, thinning out on the flanks of eruptions, and becoming modified as an anastomosing network of baculae at the apex of an eruption .

Sporoderm structure in A. fi!iculoides var. rubra is sufficiently different frorri' that of A. filiculoides, particularly in the nature of the endoperine, as to merit separate description (see f ig . 3 g-h ) .

Sporoderm thickness ea. 1 6.0 )Jm beneath depressions, reaching ea. 30.0 J,Jm in raised areas. Below depress ions, sporoderm composed of exine (ea 4.2 um) , endoperine (ea. 3 .8 u m ) , exoperine 1 (0.5 - 1 .0 )Jm) and exoperine 2 (ea. 7.0 )J m ) . Within an excrescence, endoperine can attain a th ickness of ea. 23.0 )Jm . Endoper ine conspicuously vacuolate, appear ing reticulate in sect ion, with a thick, coarsely granular mesh. El ongated alveolae (maximum diameter ea . 1 .0 )J m , except within excrescence) are arranged in a central zone between dense, narrow peripheral zones. Endoperine zonation is conspicuous within an excrescence where the basal dense zone projects upward and is separated by the vacuolate zone from the upper dense zone. The exoperine 1 is constructed as in A fi/iculoides, but with more numerous, strongly devel oped columel lae. Exoperine 2 is s i m i l ar to that of A. fi!iculoides, inc luding modification at the sites of eruptions.

CON C LUSIONS

Many specimens in herbar ium col lect ions of Azolla do not possess sporocarps, resu lt ing in on ly a l i m ited col l ecti on of each of the species bei ng ava i l able for study. However, f ive d i st inct sporoderm types are recogn ised , though the 3 - layered sporoderm is common to a l l species i nvestigated. Sporoderm structure in A fificufoides var. rubra is suffic iently d isti nct to suggest that th is variety may possibly be considered as a separate species.

In the past, too much re l ia nce may have been placed on the use of vegetative featu res for the identification of Azolfa species, l eading to incorrect determ i nation . For example, dur ing th is i nvestigat ion, col l ections attr i buted to A africana, long regarded as a variety of A pinnata ( Baker 1 886, Sweet and H i l l s 1 97 1 ) , were found to possess megaspore apparatuses of the A nifotica type. This m ight suggest that A. pinnata and A nifotica are not eas i ly separable us ing vegetative morphology .

The megaspore apparatus is bel ieved to offer the best means of defi n ing Azolla species at the present t ime, at least in itial ly , meani ngfu l vegetative d i fferences may then be establ i shed from species col l ections over a wide geograph ical area.

AC KNOW LEDG EM ENTS

The authors wish to express the i r gratitude to Mr A.C. Jermy, British Museum ( N at. H ist.) and Dr F . M . Jarrett, Royal Botan ic Gardens, Kew, for prov id ing access to herbariu m col l ections, and for the i r interest and he lp. We are also gratefu l to M i ss D .

4 1 2 F E R N GAZETTE: VOLUME 1 1 PART 6 ( 1978)

l rwi n , I mperia l College, London, for ass istance with scanning e l ectron m icroscopy, and Mr K . Purdy· of this department, for photographic woi"k.

R EFER ENCES BAK ER, J .G . 1 886. A Synopsis of the Rhizocarpeae. J. Bot. 24 : 97-1 01 . BERTELSEN , F . 1 972. Azolla species from the Pleistocene of the central North Sea area. Grana

12 : 1 3 1 -145. BONN ET, A. L-M. 1 957. Contribution a ! 'etude des Hydropteridees 3 . Recherches sur Azol/a

filiculoides Lamk . Rev. Cytol. Bioi. Veg. 28 : 1 -88. DEMA LSY , P. 1 954. Le sporophyte d'Azolla nilo rica. La Cellule 56 : 1 -60 ERDTMAN, G·. 1 952. Pollen morphology and plant taxonomy. Angiosperms. Stockholm;·539 pp. FOWLER, K. 1 975 . . Megaspores and massulae of Azolla prisca from the OU�o��ne of. the I sle of

Wight. Palaeontology 18 : 483-507. . F OWLER K . and STENN ETT·W I LLSON J. 1 9 76. The sporoderm in extant species of Azol@, ·

· Pro�. 4'th Intern. Palyn. Con f., Lucknow, lndia. Dec. 1 976.

KEMPF , E.K. 1 969a. E letronenmikroskopie der Sporodermis von kanozoischen Megasporen der Wasserfa rn·Gattung Azo/la. Paliiont. Z. 43 : 95-1 08.

KEMPF, E .K . 1 969b. Elektronenmikroskopie der Megasporen von Azolla tegeliensis aus dem Al tpleistoziin dcr Niederlande. Palaeontographica B 128 � 1 67-1 79.

MARTIN, A.R.H. 1976. Some structures in Azol/a megaspores and an anomalous form. Rev. Palaeobotan. Palyno/. 2 1 : 1 4 1 -1 69.

M ETTENI US, G. 1 847. Uber Azolla. Linnaea 20 ; 259-282. STRASBURGER, E. 1 873. Vber Azolla. Jena. SVENSON, H .K. 1 944. The New World species of Azolla. Am. Fern J. 34 : 69-84. SWEET, A .R . and CHAN DRASEKHARAM, A. 1 973. Vegetative remains of Azolla schopfii

Dijkstra from Genesee, Alberta. Can. J. Bot. 51 : 1 491 - 1 496. SWEET, A .R . and H I L LS, LV. 1 971 . A study of Azolla pinnata R. Brown. Am. Fern. J. 6 1 : 1 -1 3. SWE ET, A.R . and H I LLS, LV. 1 976. Early Tertiary species of Azolla subg. Kremastospora from

western and arctic Canada. Can. J. Bot. 54 : 334-351 .

F E R N G A Z . 1 1 (6) 1 9 7 8

MORPHOLOGY, ANATOMY AND TAXONOMY OF LYCOPOD IACEAE OF THE DARJEELING HIMALAYAS

TU H I NS R I S E N AND U . SEN Department of Botany, Kalyani Un iversity ,

Kalyan i 741 235, I nd ia .

ABSTRACT

Th is paper dea ls with the anatomy, morphology, palynology and taxonomy of lycopods of Darjeeing H imalaya. A total of 5 genera and 1 3 species are described, i l lustrated and critically circumscribed from the area for the first time, and 6 new combinations are establ ished . The altitudinal distribution of all the taxa i n different forest types i n Darjeel ing H i malaya are noted and a key for their i denti fication is proposed.

INTRODUCT I O N

4 1 3

The Lycopodiaceae a s conceived here includes the fo l l owing genera : Lycopodium, Diphasium, Huperzia, Palhinhaea, and Phlegmariurus. Most of these pl ants are sma l l , herbaceous or shru bby in natu re . Some o f them are epiphytic a n d have erect or pendent sporophytes; others are terrestr ia l and may become horizontal or erect. They have el igu late m icrophy l lous l eaves and sporangia occurring singly on the adaxia l su rface of the sporophyl l .

These plants grow in d ifferent parts of the world from the tropics to the polar regions. In I ndia they are genera l ly restricted to the H imalayas, Andaman-N icobar I s lands, and on the mountains of South Ind ia . The only important account of the l iv ing lycopods of l ndid is conta ined in the 'Notes on I nd ian species of Lycopodium with remarks on the d istribution of the genus in Ind ia , Burma and Ceylon' (Chowdhury 1 937) . Unfortu nate ly , i n th is work no attempt was made to describe and circu mscribe the indiv idual species, and no keys were designed to fac i l itate the i r identification. Moreover during the l ast three decades new l i nes o f thought and understanding have developed and have changed the earl ier generic concepts of the lycopods. The pu rpose of the present treatment is to consider the morphology , anatomy, palynology and del imitation of a l l the lycopodioid taxa of Darjeel ing in the H imalayas.

The district of Darjeel ing l ies between 26.3 1 ' and 27 . 1 3' north latitude and 87.93' and 88.53' east longitude. l t contains a total area of 1 ,873 square k i l ometres . The principa l town of the district, Darjee l ing is situated at an average al titude of 2,044 metres. The soi l is main ly composed of a l luv ium of l i ght loamy textu re ; it is commonly known as black, red and white so i l . Among these white soi l is the poorest, wh i le the bl ack one i s very rich and contains organ ic matters. The soil is covered by a layer of humus, 2.5- 1 0 cm deep. The n itrogen content of the so i l is low, wh i l e the calc ium content is h igh. The ra infa l l is m in imum during the months from November to March, whi le it is maxi mum dur ing the monsoon. Darjeel ing receives on an average 306.5 cm of rain with i n a year. Heavy rains caused by monsoons and humus work together for the development and growth of forests and vegetations of a l l k inds on the mounta ins of the Darjee l ing d istrict. The humid ity is also l ess during the winter , but gradual ly it i ncreases dur ing the monsoon and becomes h igh est in the month of July (above 90% ) . The temperature rises to about 24 C during the months of May to OCtober but decreases sharply during the winter, a lmost at a freezing point .

4 1 4 FERN GAZETTE: VOLU M E 1 1 PA RT 6 ( 1978)

KEY TO G E N ERA A. Plants isodichotomous, roots restricted to the base of the stem, sporangia caul ine or

axi l lary, spores pitted.

B. Vegetative leaves and fertile leaves similar, no definite formation of strobi l i . Huperzia

BB. Vegetative leaves and fertile leaves dissimilar, formation of definite strobili . Phlegmariurus

AA. Plants monopodia! , roots scattered throughout the stem , sporangia foliar, spores .without pits

C. Vegetative leaves di· or trimorphic, u ltimate branchlets flat with tetrastichous leaves . Diphasium

CC. Vegetative leaves isomorphic, u l timate branchlets round with spiral leaves

D. Branches erect and tree-li ke in habit, valves of the sporangium unequal , strobi l i sessi le Palhinhaea

DD. Branches ascending and u n l i ke the trees, valves of the sporangium equa l , strobi l i peduncled . . L ycopodium

GENUS H UPERZIA HUPERZIA B E R N H A R D I (in Schrad, Journ .Bot. 1 800(2) 1 26, 1 80 1 ) . The plants are terrestria l or epiphytic in habit, and are i sodichotomously branched . All the branches are functiona l ly a l i ke and grow indefin itely . The vascu lar cy l inder of the stem may be actinoste l ic or p lectoste l ic ; frequently, however, both types of the ste lar structure may occur at d ifferent - regions of the adult plant. The vegetative and reproductive leaves are s im i l ar i n shape and the latter are never aggregated i nto def in ite cones. Sporangia are borne d irectly on the stem or i n the axi l s of the sporophyl ls . The ektexine of the spore is pitted . The roots occur only at the base of the stem; i n tran�ve.rse section the xylem mass o f the root i s cresent shaped with pholem situated i n the bay .

Gametophytes are dorsiventra l , flattened and possess a d i stinct or ind istinct r im on the dorsal s ide ( Bruchmann, 1 885; Boiv in , 1 950) . Rh izoids develop o'n ly at the undersurface of the protha l l us. Sex organs are scattered ahd restricted with i n the rim.

Ghatak ( 1 965) suggests that the basic chromosome number may be x = 1 1 withi n the genus, whi_ le P ich i -Sermo l l i ( 1 958) remarks that the chromosomes of this genus were derived from a hypothetical basic number 1 7, and that the present numbers are characterized by a h i gh polyplo idy . Type : Huperzia se/ago ( L . ) Bernh. ex Schrank et Mart . Hort. Monac. 3, 1 829.

Key to the Species

A. Plants terrestrial , erect or suberect, sporophylls scattered throughout the stem ; walls of the guard cells without any l i gnified ray-l i ke thickenings; spores with truncate corners and concave or straight side wal ls; pits on the spores free, never coalescent

B. Leaves and sporophyl ls oblanceolate, not un iform in-size ; hypostomatic ; walls of the guard cells around the stomatal pore thick

C. Leaves and sporophylls thin, strongly and remotely serrated , n ever in small alternating homogeneous groups; sporangia caul ine . H. serrata

CC. Leaves and sporophylls very minutely or obscurely dentate towards the apices, always in small alternating homogeneous groups; sporangia axi l lary .

H. herteriana

BB. Leaves and sporophylls lens-subulate, entire or minutely serrated, uniform in size; amphistomatic; walls of the guard cel ls uniformly th i n . . H. se/ago

AA. Plants epiphytic, pendulous at maturity; sporophyl ls more corwded near branch tips; walls of the guard cells with ray-like l ign ified thickenings; spores with rounded corners and convex sides; at least a few pits on the spores coalescent

D . Leaves and sprophylls spreading; midrib distinct, sporangia caul ine; pits o n spores un iformly distributed both on proximal and distal surfaces

SEN & SEN : LVCOPOD IACEAE OF DARJEELING H I MALAYAS 4 1 5

E . Stem slender, 1 -2 mm in diameter; leaves a n d sporophyl ls oblong, tips of which never drawn into a sharp point; glossy on dryness, hypostomatic . H. hamiltonii

E E . Stem thick, never less than 3 mm in diameter; leaves a n d sporophylls l inear, long, tips of which drawn i nto a sharp point; amphistomatic . . H. squarrosa

D D . Leaves a n d sporophy l l s ascending (on ly occasional ly basal ones spreading) ; midrib obscure; sporangia axil lary ; pits on spores almost lacking on the proximal su rface

F . Plants usually short; l eaves and sporophyl ls soft, l inear, u n iform i n size throughout, never appressed to the ste m ; rays of the guard cel l s extending the entire lumina of the cel l s strongly l i gnified.

G . Plants never tufted; l eaves setaceous, never i ncurved a t s ides o r twisted at the base; amphistomatic; fol iar epidermal cells without any pits ; pits on spores mostly coalescent, rarely free . . H. subulifolia

GG. Plants tufted, leaves a lways i ncurved at the margins and often twisted at the base; hypostomatic; fo l iar epidermal cel ls pitted; p its on the spores free, only occasional ly coalescent . H. pulcherrima

F F . Plants long; leaves rigid, strongly appressed, lanceolate, gradual ly smaller mP.rgi ng into sporophyl ls ; rays of the guard cel l s extending half the cel l s ' l umina faintly l i gn ified ; fo l iar epidermal ce l l s strongly pitted; p i ts on the spores free, rareiy coalescent . H. laxa

HUPER Z I A SELAGO ( L) Bernh .ex Sch rank et Mart. Hort. Monac.3, 1 829 Lycopodium se/ago LSp.PI.2: 1 1 02, 1 753; Chowdhury in Trans.nat. I nst. Sci . , Ind ia , 1 : 1 90, 1 937. ( F ig. 1 a-j )

Plants are terrestrial , and usually grow on shady rocks. They are smal l , generally about 2-1 0 cm long, but u nder favourable conditions grow upto 20 cm , erect or sometimes become suberct. The stem is about 1 .5-3 mm in diameter, actinoste l ic at the basal and the distal parts while i n th.e middle region it becomes al most pectoste l ic , and exarch . The xylem rays are expanded at the periphery, and their numbers vary at different regions of the same plant. The tracheids of the f irst formed protoxylem ar·e lon g, narrow, and possess delicate, unl ignified primary wall with a series of thicken.ed annular r ings on the inside. Often adjacent ri ngs are connected by one or two vertical ly or obliquely oriented bands, but more frequently they are free from one another. The later-formed protoxylem elements possess a del icate un l ign ified primary wal l , internal to which there occurs a discontinuous system of thickening in the form of a net. The metaxylem elements develop bordered p its, the pits being circular, oval or el ongated. The cottex is composed of th i n walled parenchymatous cel l s f i l led with starch grains. The branches are isodichotomous and are of indefinite growth. Leaves are crowded, 8-ran ked, lens-su bulate, gradual ly acuminate towards the apex, and narrow towards the base, minutely serrated or very rarely entire, glossy and moderately thick. They are about 1 cm long and 1 .5 mm broad. The vein is raised on both the surfaces in fresh material but becomes obscure in dried speci mens. The epidermal cells of tha leaves are thin wal led, elongate and wavy. Stomata are nu merous and occur on both the surfaces of the vegetative and reproductive leaves. The wal ls of the guard cel l s are u niformly thin and do not show additional thickenings. The mespophy l l cells are not differentiated into pal isade and spongy tissues. Mesophyl l cells are hexagonal i n outl ine. A few irregu lar shaped air-cavities occu r between the mesophyll cells. The leaftrace is composed of a few tracheids su rrounded by parenchymatous cells.

The sporophyl ls are very nu merous and may be distri buted from the apex down towards the base of the stem . They neither form a def in ite strobi lus, nor the ster i le and the fertile zones are clearly differentiated. The basal region of the stem is, however, often sterile. Occasional ly isolated sporophyl ls occur among the vegetative leaves. The sporangia are broadly reniform , shortly stalked an d attached i n the axi ls of the sprophyl l s . The sporangia spl i t into two equal valves. A very interesting feature is the production of bu lb i l s in the axils of the leaves. The roots are basa l , clustered and dichotomously forked. The spores are tetrahedral, sub-triangular, about 4 1 u i n diameter and have s l ightly concave sides and truncate corners. The trilete mark extends u pto 2/3 of the spore's radius. Exospores are distinctly pitted; pits be ing numerous on both the su rfaces and never coalescent ( i .e. foveolate) .

HUPER Z I A H ERTE R I AN A (Kumm. ) Sen e t Sen , comb. nov.

Lycopodium herterianum Kumm. in Magyar Bot. Lap.26: 99, 1 928, a substitute name

4 1 6 F E R N G A Z ETTE: V O L U M E 1 1 P A R T 6 ( 1 978)

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F I G UR E 1 . a·i. Huperzia se/ago; k·r, Huperzia herteriana: s·z, aa-cc, Huperzia serrata. a, part of a plant {X 1 ) ; b, T .S. of caul ine stale near the base of plant {X 87) ; c-e, tracheary elements of stem {X 435) ; f-g, epidermal cel ls from adaxial and abaxial su rfaces of . lam ina respectively showing stomata, { X 1 40) ; h, sporophyll (X 3 ) ; i, V.S. through a sporangium showing axi l lary attachment {X 25) ; i . spore (X 435); k, part of plant (X 1 ) ; I, T.S. of stele near the basal region of plant (X 87) ; m, epidermal cel ls from the adaxial su rface of lamina {X 1 40 ) ; n, epidermal cel ls with p its on wal l s ( X 1 000) ; o, epidermal cells from the ·abaxial su rface of the lamina showing stomata ( X 1 40) ; p , sporophyll (X 3 ) ; q, V .S. through sporangium showing axi l lary attachment ( X 25) ; r, spore (X 435) ; s, part of plant {X 1 ) ; t, T.S. of stele at basal region of plant ( X 87); u-v, tracheary elements of ·stem {X 435 ) ; w, vegetative leaf (X 3 ) ; x, sporophyll {X 3 ) ; y, epidermal cel ls from the adaxial su rface of lamina (X 1 30) ; z , epidermal cel ls from the abaxial surface of lamina showing stomata (X 1 30) ; aa, V .S. through sporangium showing caul ine attachment (X 25) ; bb-cc, spores {X 435) .

SEN & SEN : LYCOPO D I AC EAE OF DARJ E E L I N G H I MALAYAS 4 1 7

based o n L . sikkimense Hert. L. sikkemense Hert. i n Bot. Jahrb. 4 3 : Beibl n r . 98,42, 1 909; non K. Muel l , 1 86 1 . L. /ucidulum sensu Clarke in Trans. Linn . Soc. l l . Bot . 1 : 589, 1 880. ( F ig. 1 k-r ) .

The plants grow o n rocks i n shady forests. They are smal l about 1 5-20 c m long, suberect, th ree or more t i mes isodichotomously branched. Branches are spreading and about 1 .5·2 m m in diameter. The ca u l i n e vasc u l a r cy l i nder is act i noste l i c ; its protoxylem el ements occur in con t inuous bands at the peripheral margi ns of the x y l e m arms. Tracheids of the metaxylem have bordered pits , wh ich may be round or elo ngate and u n i - or b i -seriate .

The leaves are moderately crowded, most l y 6-ra n ked, spread ing or defl exed , oblanceolate and u s u a l l y mi n utely toothed or wavy above the midd l e . They are of various s izes and a l arge leaf is about 10 m m long and 1 .5 mm broad. A l l the leaves are sess i l e and have promi nent midribs. Epidermal cel l s are rectangular i n outl i n e and have prom inently pitted wa l l s . Stomata are confined to the abax ial su rface o n l y . The guard cells are large and have slightly thick wal ls . The mesop h y l l cel l s of the l a m i na a r e und ifferentiated, but a r e mostly rectangular i n cross section . T h e ai rspaces between the mesophy l l cel ls are large but few in n u mber. The sporoph y l l s resemble the vegetative leaves in s hape but are u s u a l l y shorter in s ize. They usua l l y occur in smal l groups a l ternating with the zones of ster i le leaves. However, isolated sporophyl ls may occ u r among ster i l e leaves. The sporangia are borne on short stal ks, and are attached i n the ax i l s of the leaves; they deh i sce by apical suture, which d ivides the jacket i n to two equal valves. The spores are tetrahedra l , subtriangular, about 26 u i n diameter, and have many circular pits, which are never coalescent. The pits occ u r both o n the distal and the proximal face. The tri lete mark is extended upto the margi n . The s ide wal l s are concave, and the corners are truncate.

The roots both morphol ogica l l y and anatomica l l y resemble those of H. se/ago.

HUPE R Z I A S E R R ATA (Thunb. ) Roth m . Feddes Repart. 54 : 58-, 62, 1 944. Lycopodium serratum Thu n b . Fl. Jap ., 34 1 , 1 784; Clarke in Trans. Linn. Soc. Land . , 1 1 . Bot 1 : 59 1 , 1 880. ( F ig . 1 s-z, aa-cc ) .

Plants are terrestrial and grow i n moist and deep shady places on h u m u s r ich soi l . They are suberect, about 1 5-40 cm long, and 3-4 ti mes isodichotomou s l y forked. The branches are spreading , and about 2-3 m m i n diameter. The vascu lar cy l i nder is actinoste l i c at the basal ret i on but h igher up gradua l l y changes i nto a plectoste l i c con dition . At the d i stal end of a branch the vasc u l a r cy l i nder rega i n s its act i noste l i c state. The tracheids of the proto-and metaxylem are s i m i l ar to those of H. se/ago. The leaves are large or smal l , t h i n , oblanceolate, crowded , sess i l e and characteristical l y serrated. They have a prom i n e n t midr ib, narrowed base and an acute apex. A la rge leaf is about 3 cm long and 3-5 mm wide. The small and large leaves are i n termi xed with one another. The small leaves usua l l y bear sporangia, but often sporangia occur on la rge l eaves. The epidermal cells o f the leaves are el ongate, s i n u ous, and bear stomata o n l y on the abax ia l surface. The wal l of the guard cel ls adjacent to the stomatal pore is heavi l y and u n i formly thickened. The mesophy l l cells are not differentiated i nto spongy and palisade cells and are of i rregu lar shape and size. The sporophy l l s may be borne all a l o n g the stem excepting the base. Occas ional ly the sprophyl ls and the vegetative leaves form al ternate ferti l e and ste r i l e zones . The sporangia are cau l i n e , ren i form but without any sinus on the proximal wa l l , larger than the base of the sporophy l l , and are borne on a massive sta l k . The jacket of the sporangium i s composed of ce l l s with wavy wal ls a n d spl its i nto two equal valves. T h e spores are about 3 1 u i n di ameter, triangu l a r , but appear hexagonal due to tru ncate corners. T h e s ide wa l l s are concave. E ktex i n e is t h i c k and pi tted . The p i ts are rou nd, non-coalescent, cl osely spread excepting around the tetrad scar where only a few of them occu r. The tr i lete mark extends up to the margi n .

HUP E RZ I A SUBULI FOLIA (Wa l l . e x Hook e t G rev . ) Sen e t Sen , Comb. Nov.

Lycopodium subulifo/ium Wal l . ex Hook. et Grev . Icon . F i l . 1 : t. 49, 1 827. L. setaceum Ham. ex D . Don . var subu l ifo l ium Wal l . apud Clarke in Trans . L inn .Soc . l l . Bot. 1 : 590, 1 880. ( F ig. 2 a-k ) .

Plants grow as epiphytes usu a l l y i n dark shady forests. They are wea k , pendu l o u s , non spreading and fork isodichotomously two or three t im es. Usual ly a p lant atta i n s a height of 1 0-25 cm, but u nder favourable conditions of growth i t may be more than 50 cm l o n g . The stem is 1 -2 mm in dia meter, actinoste l i c but often the ra diating xylem arms become separated from one another, showing a tendency towards formation of i rregu lar plates. The proto x y l em el ements have

4 1 8 F E R N GAZETTE: V O L U M E 1 1 PA RT 6 ( 1 97 8)

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8 f

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gg

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hh dd F I G UR E 2. a-k , Huperzia subulifolia; 1-r, Huperzia pulcherrima; s-z, aa, Huperzia hami/tonii; bb-hh , Huperzia squarrosa. a, part o f plant ( X 1 ) ; b, T . S . o f stele near proximal end o f plant ( X 87) ; c-f, tracheary elements of stem (X 435 ) ; g, epidermal cells from abaxial surface of lamina showing sto­mata (X 1 30) ; h, sporophyll (X 3 ) ; i , V .S. through a sporangium showing its axi l lary attachment (X 25) ; j-k, spores (X 435) ; I, part of plant (X 1 ) ; m, T .S. of stele near proximal end of plant (X 1 40) ; n, epidermal ce l ls from abaxial surface of lamina showing a stoma (X 300 ) ; o, epidermal cells from the adaxial surface of·lam ina (X 1 40), p, sporophyl l (X 7 ) ; q-r, spores (X 640) ; s, part of plant (X 1 ) ; t , T .S. of cau l ine stele near m iddle region of plant (X 87) ; u , tracheid from stem ( X 435 ) ; v, epidermal ce l ls from adaxial surface of lamina (X 1 30) ; w, epidermal ce lls from abaxial surface of lamina ( X 1 30 ) ; x , sporophyl l (X 3 ) ; y , V.S. through a sporangium showing caul ine attachment (X 2 5 ) ; z , aa, spores ( X 43 5 ) ; bb, part of plant (X 1 f ; cc, T .S. of caul ine stele just above base of plant (X 87) ; dd, epidermal ce l ls from abaxial su rface of lam ina showing stomata (X 1 40) ; ee , sporophyl l (X 5); ff,

V .S . through a sporangium showing its caul ine attachment (X 25) ; gg-hh , spores (X 435) .

SEN & SEN : LYCOPO D IACEAE O F DARJ E E L I N G H I M A LAYAS 4 1 9

annular o r a n n u l ar-he l ical hybrid type of th ickening. The vertical bands connecting two adjacent r ings are mostly thin but often become considerably thic kened extending up to % of the thic kness of the tracheids. The rings are of various s i ze s ; some are wel l fitted with i n the surroun d i n g wal l , wh i l e others are attached only a t one s i de o f t h e wa l l . There are also r i ngs which are very smal l and are attached to one another by the vertical bands only. The metaxylem e l ements have bordered pits; the pits are round, oval or e longate.

The leaves are l i near-subu late, t h i n , setaceous, ent i re ascending and crowde d . They have a flat base and a gradual l y narrowed acute apex. There is no i ncurvi n g or twisting of the lamina. The midri b is inconspicuous. Fol iar epidermal ce l ls are short and without any p i ts . Stomata develop on both the su rfaces. The guard cells are with conspicuous ray l i ke thicken i n gs , radiati n g from the wall encirc l i n g the stomatal pore to the peripheral wal l of guard cel l s . The mesop h y l l cel l s are oval to elongate. The sporophy l l s are usual ly crowded towards the distal region but occasion a l l y develop in the basal region o f the plant. The sporangia are a x i l l ary, l ong stalked, larger than the base of the sporophyl l , reniform and are without any s i nus at the proximal marg i n . The spora ngia! jacket is composed of wavy wa l l ed cel ls and shows apical dehiscence. Spores are subtr iangu l a r and have convex or flat s i des and rounded corners. They are tetrahedral and p i tted . The p i ts are close l y distributed except i n g arou n d t h e tetrad scar where they are few in n um ber. They a r e generally un ited with one a n other and o n l y occasi o n a l l y free. The t r i l ete mark extends upto the margi n . The spores measure about 34 u in d iameter.

HUP E R Z I A PULCH E R R I ��A (Wal l . ) Sen et Sen , Comb. Nov.

Lycopodium pu/cherrimum Wal l ich List n . 1 1 5, 1 828; Hook. et Grev . I co n . F i l . t. 38, 1 929. ( Fi g. 2 1 -r) .

Plants are epiphytic, pendent, 1 5-20 cm l ong and grow in shady forests. Branches are isodichotomous, 2-5 times forked at short i n tervals, espec i a l l y near the distal region and become tufted.

The cau l i n e vascu lar c y l i nder is p l ectostel ic and is composed of tracheids very s i m i l a r to those of Huperzia subulifolia. The leaves are crowded, l i n ear, upto 8 mm l ong and 0.5 m m wide, never appressed to the stem, general ly ascending and only occasional ly spreading at the basal regi o n . They are sessile, havi ng a flat base and typical l y i n rol led enti re margi ns . The fol iar tip is often cu rved i n ward and the m i drib is i nconspicu ous. The epidermal ce l ls of the leaf are elongate and have a lmost straight and p i tted wa l l s . Stomata are scattered on the abaxia l surface and have 5-6 rays exte n d i n g the entire width of the guard cel l s . On the adaxial su rface of the leaf they occ u r only at the basal regi o n . T h e mesop h y l l ce l ls a r e a l m ost c i rcular and have large a i r spaces between the m . The sporophyl ls resemble the vegetative leaves. Sporangia are axi l l ary and exceed the width of the sporophyl l s . They have a broad but shal low sinus and a s len der stal k. Sporangia! wall is sinuous and spl its into two equal halves. Spores are tetrahedral, pi tted, subtriangu l a r and have convex margi n s and rounded corners. Pits are usual l y free and only occasionally coalescent. They occur i n la rge n u m bers on the distal surface but few on the prox imal surface. The tr i lete mark extends to the margi n . The spores are about 30.5 u i n diameter.

H UP E R Z I A HAMI LTO N I I (Spring) Sen et Sen . Comb. Nov.

Lycopodium hamiltonii Spring ex Hook .et Grev. in Hook. , Bot. Misc. ,2 : 366, 1 83 1 . Clarke in Trans .L inn .Soc . Lond. , 1 1 Bot. I : 590, 1 880. ( Fig . 2 s-z, aa) .

Plants grow as epiph ytes in shady places and rarely as l i thophytes in rather exposed s i tuations . They are usual ly weak, pendu l ous and genera l l y atta i n a height of 1 0-25 cm. The stem i s s lender, about 1 -2 m m i n d iameter a n d isodichotomously forks 2-4 t i mes. Vasc u l a r cyl i nder i s plectostelic and t h e peripheral protoxy l e m poi nts often touch t h e single layered pericyc l e . Tracheids a r e bordered pitted, t h e pits bei ng u n i ser iate, round o r e l ongated. T h e leaves are th ick, glossy when dry , f irm, sess i l e, crowded, oblong, spreading, 7- 1 5 m m l ong and about 5 m m wide. They have a narrow base, an ent ire marg i n , and a distinct m i dr ib . F o l i a r epidermal cel ls are h i g h l y thickened and a r e without any p i tt i ngs. T h e adaxia l epidermal c e l l s a r e larger i n s i ze a n d are without any stomata . The guard cells of the stomata, which are nu merous on the abax ia l surface, have ray l i ke thicke n i n g exte n d i n g u pto the m i ddle of the guard cel l s . The leaf in transverse secti on is rather thick and shows m a n y layers of mesoph y l l cel ls hexagonal in outl i n e . The mesophyl l cel ls ly ing i m mediate l y below the upper epidermis are more compact and smal ler than those situated o n t h e abax ia l su rface of t h e leaf.

The sporophyl ls resemble the vegetative l eaves. They are usual ly aggregated i n the apical

420 FERN G A Z ETTE: VOLUME 11 PA RT 6 ( 1 9 78 )

part of the plant and often occupy the entire apical hal f o f a branch. Occasional l y a n isolated sporophyll may occur among the vegetative leaves in the basal region of the plan t . The sporangia are large, reniform, and are borne on long stalks, a t tached directly on the stem. The spores are subtriangular, tetrahedral, and have rounded corners and convex sides. E k texine is thin and pits are dense and laterally united with each other. The spores are about 33 u in diameter.

H UPE R Z I A SOUAR ROSA ( Forst.) Roth m . Feddes Repert. 54 : 58-62, 1 944. Lycopodium squarrosum Forst., Prodr. F l . Austral , 86, 1 786. Clarke in Trans. L i n n . Soc. l l . Bot.1 : 591 , 1 880. ( F ig. 2 bb-hh ) .

Plants are eplphytic and hang from the bark of the trees. They are deep green in colour, 1 0-70 cm long and never less than 3 mm i n diameter a t the base . They branch 3-5 times mainly towards the distal regiory. Stem is actinostelic at the basal and distal regions, elsewhere it is plectostel ic. The radial xylem arms o·f the actinostele are broadened at the periphery. Tracheids have bordered pits; the p i ts are round, oval or el o11gate. uniseriate but show a tendency towards biseriate form.

The leaves are l i near, though, c rowded, spreading and twisted a t the base when dry. Their t ips are drawn i n to sharp spines. The margin of the leaf is enti re, and the midri b is disti nct. A leaf is about 20 mm long and 2 mrn wide. The foliar epidermal cel ls have highly cuticularised thickened walls but no pits. They are rather rectangular in shape, and have minutely wavy walls. Stomata occur on both the sur faces of the leaf. The guard cells have 5-6 inconspicuous ray l i ke thickeni ngs extending from the wall adjacent to the stomatal pore and ending blindly long before reaching the periphery o f the guard cells. The mesophyl l cells are angular in cross section and the i ntercel l u l ar spaces between them are conspicuously smal l . Sporophylls are either aggregated at the tips of the branches or occur among the vegetative leaves. The sporangia are reniform, larger than the base of the sporophyl l and are borne on short stalks a ttached directly on the stem.

The spores are tetrahedral , subtrlangular and have convex sides and rounded corners. The ektexine Is thin and pitted. The pits are m inute. and coalescent; they occur In large numbers over the distal surface. The trllete mark extends upto 2/3rds of the spore's diameter. The spores are about 39 u in diameter.

HUPE R Z I A LAXA (Presl ) Sen et Sen. Comb Nov.

Lycopodium laxum Presl in Reliqu iae Haenkeanae, Vol . 1 : 83, 1 825. ( F ig. 3 a-j ) . Plants are epiphytic, and usually grow on large trees i n dark forests. They are slender,

pendulous, n on-spreading, and 3-4 ti mes isodichotomuusly forked, the successive points of forking being widely apart. A mature plan t Is about 80 cm long, and about 4 mm i n diameter near the proximal end. The stem near the basal region is tough, actl nostelic and characterist ically develops 5-7 protoxylem points; i t , however, becomes plectostelic towards the distal part. Early formed protoxylem elements are long, narrow and possess a thin delicate unl ignified primary wall wi th a series of annular thicken ing.s on their inside. The later formed elements are broad and exhibit reticulate type of pittings. Metaxylem tracheids possess circular to oval unseriate simple and bordered pits.

The leaves are lanceolate, thick, rigid, ascending, always pointing towards the apex, strongly appressed., decreasing in size towards the apex and merging into the sporophy l ls . A mature leaf is en tire, convex on the abaxial su rface, and 4-7 mm long; about hal f of i ts proximal part forms the sheathing base. Foliar epidermal cells are short, pitted and rectangular to hexagonal in su rface view. Stomata develop on both the surfaces, but they are lesser i n number on the abaxial su rface. The guard cells have 6-7 fa intly l igni fied rays extending hal f way between the margin of the stomatal pore and their peripheral wal ls. Sporophylls resemble the vegetative leaves and do not form distinct strobil i . The sporangia are axillary and have a deep sinus accommoda ting the slender stalk. The sporangia! jacket is composed of wavy walled cells. Spores are subtriangular, about 33.5 u in diameter and pitted. The pits are few on the proximal surface but are numerous on the distal side. The tetrad scar extends to the spore's margi n .

G E N US P H LEGMA R I U R US

PHLEGMA R/URUS ( H E R T E R ) H O L U B ( i n Presl ia , 36 : 1 7 , 2 1 , 1 964) . Plants are epiphytic and pendulous in habit. The branches are regu larly d ichotomous and bear strongly differentiated strobi l i at the t ips of the u ltimate branches. The strobi l i are

SEN & SEN : LYCOPODIACEAE OF DARJEE U NG H I MALAYAS 421

FIGURE 3 . a-j. Hupenia laxa. a, part of plant (X 1 ) ; b, T.S. of stele near middle of plant (X 87) ; c , vegetative leaf with sheathing base ( X 7) ; d, epidermal cells from abaxial surface of lamina ( X 87) ; e , epidermal cells with numeroUf ' pits ( X 640) ; f , epidermal cells from adaxial �urface of lamina showing numerous stomata ( X 53) ; g . stoma ( X 640); h , sporophyll (X 7) ; i -j , spores

(X 43J)) .

slender, repeatedly d ichotomously forked and r�re ly the tips of the cone axes prol iferate into vegetative bran­ches. Ray-l ike thicken ing occur around the stomata'! pore . The sporophyl ls are small and d ifferent from the vegetative leaves. Sporangia ar.e borne on slerider stal ks and are attached at the axi ls of the sporophyl l s . The spores are p i tted.

Roou are a�re�nd u �e �� of the stem.

The gametophytes a re subterra­nean , ramified, cy l indrical, e longate and saprophytic in habit. The sex organs occur between the scattered rh izo ids (Bruchmann , 1 885; Boiv in , 1 950) . Ghatak ( 1 965) suggests that basic chrosome number of the genus is n = 1 7 . Type : Phlegmariurus phlegmaria ( L .) S�n et Sen, comb. nov (Hoblu I. e. designated the speciesph/egmaria as the type of Ph/egmariurus, but d id not transftlr any epithet to the new genus. )

PH LEGMA R I U R US PHLEGMARI A

(L . ) Sen et Sen , Comb. nov.

Lvcopodium phlegmarium L . Sp. P I . 2 : 1 1 0 1 , 1 753. ( F ig. 4 a-j ) .

Plants are epiphytic, weak and pend­ulous; they usual ly occur on the bark of the trees, and are about 30-50cm l ong. The stem is isodichotomously forked, and

.is rooted at

the base pnly. The vascular cyl inder of the stem is a plectostele. The xylem is exarch and the tracheids have elongate, oval or round, un iseriate or multiseriate bordered pits. Vegetative leaves are spreading, ovate­lanceolate and are closely arranged. They

have a prominent midrib, herbaceous acute apex and a broad base. The margin of the leaf is entire . The epidermal cel ls of the lamina on both the surfaces are sinuous and they bear stomata only on the abaxial surface. The wall of the guard cells surrou ncjing the stomatal pore is thickened and have rays traversing about half the way between the inner and outer wal ls of the guard cells. The mesophyll cel ls are of variable shapes and sizes; numerous air spaces occur between the cel l s of the mesophyl l .

The sporophylls are very distinct from the vegetative leaves, 1 .5 m m long and 1 m m wide, and form well organised, slender, repeatedly dichotomously branched strobil i . The strobili are spreading, slender and sessi le. The sporophyl ls are very smal l and bract l i ke in appearance. They are wrinkled on the back but are n ot cuspidate . The sporangia are shortly stalked, large, caul ine, and have apical dehisce-nce. Sterile bracts often occur at the basal · region · of a strobi lus. The spores are smal l , subtriangular and have straight or convex sides. They are pitted and foveolate, the pits being minute, numerous and equally distributed on distal sides. Spores are about 35 u in diameter.

422 F E R N G A Z ET T E : V O L U M E 1 1 P A R T 6 ( 1 9 7 8 )

q

� k

0 0

00

0 d

f£>1 � @>

{i! I �

n

p F I G U R E 4, a-i . Phlegmariurus ph/egmaria; k · u , Pa/hinhaea cernua. a, part of a pl an t w i t h

dich oto m o u s l y bl a nched strob i l u s IX 1 ) ; b , T _S . of ste l e near m i dd l e regi on o f s t e m IX 53 ) ; c - d ,

tracheary e l e m e nts of s te m I X 435) ; e , epidermal c e l l s f r o m aba x i a l su rface of l am i na s h o w i n g

stomata IX 1 40) ; f , e p i d e r m a l c e l l s from adax i a l su l face of l a m i n a IX 1 40 ) ; g , spo rophy l l IX 1 8) ; h ,

V.S. t h rough a spora n g 1 u rn showing a x i l l ary a t tac h m e n t I X 53 ) ; i - i , spores I X 435) ; k , p a rt o f stem I X 1 ) ; I , T .S . of ste!e near middle region of stem IX 87) ; m -n , tracheary e l em e n ts of stem I X 435 ) ; o , e p i d e r m a l ce l l s from a b a x i a l su rface o f l a m i n a showing stomata I X 1 40) ; p , sporop h y l l I X 1 8) ; q-r, m i n u te h a i r s from base o f i ea f I X 87) ; s , V S . t h rough a sporan g i u m s h owi n g fo l i a attac h m e n t

IX 53 ) ; t-u , s p o r e s IX 435 ) _

t

S EN & SEN : LYCOPO.D !ACEAE O F DARJEELING H I MALAYAS 423

G EN US PALH I N HA EA

PA LHINHAEA F RANCO ET VASC. ( i n Vasconce l los et Franco, Bol . Soc. Broter. ser.2, 41 : 25, 1 96 7 ) . Plants are te�restria l and with tree-l i ke lateral shoots spreading from the -creeping stem. The erect lateral branches are unbranched towards the base and the u ltimate t ips of the branchlets are terete. Vascular cy l inder of the stem is usual l y a m ixed haplostele. The creeping stem roots at i ntervals . The vegetative leaves are isomorphic and bear ha i rs . The sporophy l l s are aggregated i nto cones and the penduncles of the cones are wanting . The sporangia are fol iar and d ivides into two unequal valves. Spores are rugulate .

Gametophytes are more or less conical with tapered and pointing downwards; their truncate ends bear numerous lobes. Antheridia and archego n ia are located between the bases of the lobes (Bruchman n , 1 885; Boiv in , 1 950) .

Pich i Sermol l i ( 1 959) and Ghatak ( 1 965) state that the chr·Jmosome of this genus had an origin from a hypothetical base n"u m ber 1 3 . Type : Palhinhaea cernua ( L. ) Franco et Vase. i n Vase . et F ranco, Bol . Soc.Broter.Ser. 2, 41 J 25, 1 967.

PALHI NHAEA C E R N U A ( L .) Franco et Vase. Lycopodium cernuum L. Sp . PI 2 : 1 1 03, 1 753. ( F ig. 4 k-u )

Plants are with tree-l ike branches, spreading from a creeping stem which roots at intervals. The stem is mixed haplostelic. Metaxylem tracheids have scalariform. bordered or simple pits. The pits may be in one or two rows.

The leaves are l inear, membranous, sessi le, densely crowded and spreading on ultimate branches. They have a distinct midrib and bear hairs at the basal region of the lamina. Fol iar epidermal cells are very long and narrow, sl ightly wavy and without any pit on their wal ls . Stomata pccur on both the surfaces. The wall of the guard cel ls surrounding the stomatal pore are s l ightly thickened. The sporophylls are broad, ovate, ascending and are densely ci l iated. They are aggregated into definite sessi le, strobil i . There may be over one hundred strobili in a plant. Ari important feature is the presence of some cells in sporangia! stalk resembl ing the transfusion tissue.

The sporangia always dehisce into two unequal valves. Spores are rugulate on the distal side; their proximal surface is unornamented and the triradiate scar is obscured in a groove. The diameter of the spores is about 29 u .

G EN US D I PHAS I UM

DIPHAS/UM P R ES L EX ROTH M A L E R ( i n Feddes Repert. 54:64, 1 944). The p lants are always tetrahedrai and monopodia l ly branched . The main stem is prostrate and grows indef in itely . Tips of the ult imate branches are a lways f lat and bear tetrastichous leaves. Vegetative leaves are d i - or tr imorph ic. Vascu lar cy l i nder i s pluctoste l ic . The vegetative and reproductive leaves are diss imi lar i n shape, and the latter are aggregated into defin ite cones. Sporangia are fol iar, dehisce i nto two equal valves. Ektex ine of the spore is reticu l ate ly thickened:

R oots are scattered throughout the main stem . The gametophyte is an u pright steep sided cone . lt is subterranean , radial ly

symmetrical and has· a cuspidate upper. end. The. subterranean portion of the gametophyte is composed of d ifferent types of tissues. Antheridia and archegonia a re produced on the broad cuspidate u pper end ( Boivin , 1 950) .

The basic chromosome n um ber x = 1 2 has been suggested by Ghatak ( 1 965) but Love and Love ( 1 958) state that the basic number i s x = 8. Type : .Diphasiumjussiaei! ( Desv.ex Poi r in Lam.et Poir; Lycopodium jussiaei) Presl ex Roth ., Feddes Repert. 54 : 64, 1 944.

424 F E R N GAZETTE: VOLUME 1 1 PART 6 ( 1 9 7 8 )

KEY TO THE SPECIES

A. Branches of short aerial stems never flabel loid; strobi l i peduncled, term inal , 1 -5 on a peduncle, 4-5 cm long. Sporangium borne on a massive stal k. No thickening in the guard cel l s around the stomatal pore . D complanatum

AA. Branches of short aerial stems always flabel l oid, strobi l i mostly se.ssile, 1 , rarely 2 on a branch tip, about 2 cm long. Sporangium borne on a slender sta lk . Wall of the guard cel l s around the stomatal pore th ickened . . , D. alpinum

DI PHASI UM COMPLANATUM ( L. ) Roth m . Feddes Repert. 54 J 64, 1 944. Lycopodium complanatum L . Sp .PI . 2 J 1 1 04, 1 753. ( Fijj. 5 a-j ) .

The plants are terrestrial and prostrate; they are either shal lowly buried in surface l i tter o r superficial o n soi l . The trai l i ng horizontal stems are 1-2 mm thick and produce widely separated reduced leaves. Aerial stems are ascending, smal l , much branched and becomes flattened at the apices. These branches are l i mited in growth and never flabel loid. Stems are plectostel ic and have the protoxylem points at the ends of the xylem plates. The pericycle is one layered and is surrounded by a si ngle layered endodermis. The endodermal cells are large, barrel shaped, thin wal led.

Roots are adventitious, terete and are scattered throughout the stem. Leaves on the creeping stems are isomorphic; they are nearly l inear to narrowly lanceolate

and have acute apices. On the buried stems the leaves are spatulate. Leaves on the u l timate branchlets are 4-ranked; they are scale l i ke and may be trimorphic. Such leaves are pouch-l i ke, lanceolate or narrowly deltoid. The epidermal ce l l s are h igh ly corrugated nad have conspicuous pits on their wal ls. Stomata are present on both the surfaces. The wall of the guard cells around the stomatai pore is thin. Transverse section of a leaf shows loosely differentiated thin-walled, roundish· . or irregularly shaped parenchymatous cells with conspicuous air spaces. The mesophyl l cells on the upper side are large and have a tendency towards forming palisade cel ls .

The sporophyl ls are aggregated i n to strobi l i , borne on short lateral branches. The peduncle is slender, dichotomously branched, not very long and bears alternately arranged leaves. The sporophylls are broader and larger than the vegetative leaves, and have broad base and gradual ly narrowed apex. Their margins are scarious. The sporangia are borne on massive stalks, fol iar, and dehisce into two equal valves. The spores are tetrahedral and subtriangular. The tetrad scar extends to the margin. The ektexine is reticulate on the distal side and ' the lamellae project ou t at the periphery. The spores are about 3 7 1J in diameter.

DIPHASIUM A LPI N UM ( L. ) Rothm. Feddes Repert. 54 : 64, 1 944. Lycopodiu_m alpinum l.Sp. PI 1 1 04, 1 753. � F ig . 5 k·r)

Plants are terrestrial, dwarf and trail over or just beneath humus or mossy stones. The short lateral branches are erect, 2-3 times dichotomously forked, flabelloid and are determinate in growth. The u ltimate tips of these branches are flattened, while the remaining part of the stem is usually terete. The vascular cylinder is plectostel ic. Tracheids of the metaxylem have scalariform and bordered pits. The pits are small rou nd, ova l , elongate or mixed; they may be u niseriate or multiseriate.

The vegetative leaves on the main axis are spirally arranged. They are lanceolate with narrow base and acute apex. The margins of the leaves are slightly serrated towards the tip. Leaves of the ulti mate branchlets are heteromorphic and arranged in 4 rows; they may have well developed blades and decurrent bases, or they may be broad, lanceolate with rounded or acute apices. Some of these leaves are strongly divergent and have rolled margins, whi le others are flat and spreading. The epidermal cells of both the surfaces of the leaf. The wal l of the guard cells around the stomatal pore is u n iformly thickened.

Sporophylls are arranged into strobi l i , which are borne singly or in pairs at the tip of each ferti le branch. The strobili are generally sessile. The sporophylls are deltoid to subcordate; they have entire to faintly erose, rounded margins and tapering apex. The sporangium is fol iar, smaller than the basal broad portion of the sporophy l l . l t is borne on a slender sta l k with a flat base, and dehisces into equal valves. Spores are tetrahedral , subtriangular to round with convex sidt:s. Ektexine is lopho-reticulate. The reticulation is more conspicuous on the distal side than on the proximal surface. Spores are about 36 1J i n diameter including the reticulum, which often tends to break arou nd the tetrad scar.

SEN & SEN : LY C: OPOD I A CEAE O F D A R J E E L I N G H I M A LAYAS 425

FIGURE 5 . a-i . Diphasium complanatum; k-r, Diphasium alpinum; s-z, aa, Lycopodium clavatum. a, part o f plant ( X 1 ) . b, T.S. of stele near the m i ddle region of plant (X 87) ; c , tracheid with elongated bordered pits (X 435 ) ; d , epidermal c e l l s from abaxial surface of lamina (X 87) ; e-f vegetative leaves (X 6); g , sporoph y l l (X 6); h, V.S th rough the sporangium showing fo l iar attac h m e n t ( X 25) ; i -L spores ( X 43 5) ; k , part of plant ( X 1 ) ; I , tracheid from stem (X 435 ) ; m , epidermal cel ls from abaxial su rface of lamina showing stomata ( X 1 30) ; n , vegetative leaf ( X 6 ) ; o, sporophyl l ( X 6); p, V.S. through a spora n gi u m showing fol iar attachment (X 25) ; q r, spores ( X 435 ) ; s , part o f plant ( X 1 ) ; t , T.S. o f stele near m i ddle region of pl ant ( X 87) ; u , tracheid with circu lar bordered pits ( X 435); v , epidermal cel ls from abaxial su rface of l a m i n a - ( X. 1 40) ; w , vegetative leaf ( X 6 ) ; x, sporophyl ( X 1 0) ; y , V .S. through a sporangi u m show i n g fo l iar attac hment

(X 25) ; Z, aa, spores (X 435 ) .

426 F E R N GAZETT E : VOLUME 11 PA RT 6 (1978)

G E N US LYCOPO D I U M

L YCOPODIUM L I N NAEUS ( i n Sp .PI .2 : 1 1 00, 1 753) . P lants are terrestria l , creeping and have sha l lowly to deeply buried rh i zome. The vegetative leaves are isomorphic, spira l ly arranged, and are sharply d isti nct from the sporophyl l s . The sporophyl ls are aggregated i nto cones. The cones are term inal and u sua l ly peduncled. The sporangia are fol iar and d iv ides i nto two equal valves. Gametophytes are subterranean, short, con ical or b i lobed . There is no i nternal d i fferentiation of cel ls . The u pper flattened end of the gametophyte bears a d istinct and conti nuous rim ( Boivin , 1 950) .

Pich i Sermoll i ( 1 959) and Ghatak ( 1 965) state that the chromosome i n this genus i s referable to the hypothetical basic number 1 7. Type : Lycopodium Clavatum L. Sp. PI 2 : 1 1 0 1 , 1 753.

LYCOPODIUM CLAVATUM L. Sp. PI . 2 : 1 1 0 1 , 1 753. Clarke in Trans. L inn . Soc . Lond . , 1 1 , Bot., 1 : 592 , 1 880. ( F ig . 5 s-z , aa)

Plants are terrestrial and prostrate. The rhizome is superficial or sha/lowly buried, long and indefinite In growth. l t produces small several t imes dichotomously forked lateral branches of defin i te growth. The lateral branches are soft round and sh iny, and bear dense leaves. The stem Is plectostelic and tracheids are bordered pitted. The l eaves are small about 7 mm l ong, linear and are drawn i n to long pointed almost hyal ine hair-l i ke structures. The bases of the leaves are broad and rounded and the margins are entire. The epidermal cel ls of the leaves are narrow, elongate, and densely pitted. Amphistomatic guard cells have unifromly 1hickened walls. Three or more strobi l i are grouped on a peduncle. The peduncle is slender, about 15 cm long, and bears bracts . The sporophyl ls are broadest In the middle, and abruptly narrowed to a long poi n ted hyal ine hair·l i ke structure. Their margin is serrated. The sp·orangla are reniform, stalked, fol lar and almost cover the lower portion of the sporophyl l . The sta lk is broader than long. The jacket of the sporangium deh isces i nto two equal valves.

The spores are roundish to subtriangu lar, lophoreticulate; the reticu lum on the ektexine projects out at the periphery and breaks up irregularly around the tetrad scar. The tri lete mark extends upto the margin . The spores are yel l ow and 37 u in diameter.

COM M E NTS ON D I ST R I B UT I O N I N T H E D I STR I CT

Most of the taxa featured i n th is artic le were widely d istributed i n the d istrict even some twenty years ago, but u n fortunate ly many of them are i n i m m i nent danger of at least local extinction through the actions of mankind . The awesome fact is that once a species becomes extinct, no amount of human i n genu ity can resurrect i t aga i n . But it is not at all d ifficu lt to conserve a species i f some determ ination i s employed by man for i ts defence.

The fol lowi ng is the l ist of p laces of known continued occurrence of different taxa : Huperzia se/ago : Senchal ( 2448 m ) . Tiger h i l l (2550 m ) , Bi janbari ( 1 820 m ) H. serrata : Darjeel ing Cart Road (2250 m ) Bi janbari ( 1 820 m ) . Sencha l ( 2448 m ) . Takedah ( 1 800 m ) , Bhutia Basti ( 200 m \ , Palmajua-R imbick (2300-2200 m ) H. herteriana : Senchal ( 2448 m ) . B ijanbari ( 1 820 m ) . Jalapahar (2285 m ) , Sandakphu (3500 m) H. hamiltonii : Senchal (2448 m ) , Darj ee l i ng Cart Road (2044m) . Kurseong ( 1 350 m ) H. pu/cherrima : Kal impong ( 1 182 m ) . Lolagaon ( 1 520 m ) H. subulifolia : Lebong forest ( 1 500 m ) H. squarrosa : Kal impong ( 1 1 82 m ) H. taxa : Lolagaon ( 1 520 m ) Ph/egmariurus phlegmaria : Sukhna forest ( 1 00 m ) Pa/hinhaea cernua : Birch h i l l ( 2300 m ) . Lebong ( 1 970 m )

SEN & SEN : LYCOPO D I ACEAE O F DARJEE L I N G H I MALAYAS 427

Diphasium complanatum : Sandakphu (3400 m ) D. alpinum : Tonglu (3 1 00 m ) , Ch iabanjan (3300 m ) Lycopodium clavatum : Lebong ( 1 700 m ) , Lolagaon ( 1 520 m ) , Takedah ( 1 800 m ) , Ka l impong ( 1 300 m ) , B i rch b i l l ( 2300 m ) , Peshok (2400 m ) , Chictbanjan. (3300 m ) , Sandakphu (3400 m ) , Tonglu (3 1 00 m )

The altitud i nal d istr ibution of 1 3 species o f lycopods occurring i n d ifferent types of forests in Darjeel ing D istrict is presented in the fol lowing table : Alpine forest (above 3,900 m ) Cold temperate·su balp ine forest

(2,700 - 3,900 m ) Warm temperate forest

( 1 ,500 - 2,700 m )

Tropical-subtropical forest (upto 1 ,500 m )

Huperzia herteriana, Diphasium complanatum, D. alpinum, Lycopodium clavatum

Huperzia taxa, H. selago, H. serrata, H. harteriana, H. hamiltonii, H. squarrosa, Lycopodium clavatum, Palhinhaea cernua

Huperzia serrata, H. hamiltonii, H. pulcherrima, H. subulifolia, H. squarrosa, Phlegmariurus phlegmaria, Lycopodium clavatum

l t can be seen that a lthough lycopods grow pro I ifica l ly in the tropical-subtropical to warm temperate forests, none of the species ascend a bove the suba lp ine forest.

AC KNOW LEDG EM ENTS

We are very grateful to Professor R . E . Holttum who gu ided many of our thoughts in the many hours of discuss ion; however, the taxonomic and nomenclatural conClusions h ere presented are those of the present authors. We are particu larly indebted to Professor S.P. Sen for h is i nterest in the work.

R E F ER E NC ES

BO I V I N , B. 1 950. The problem of generic segregates in the form-genus Lycopodium. Amer. Fern J., 40 : 3 2-4 1 .

BRUC H M A N N , H . 1 885. Das prothal l ium van L ycopodium. Bot. Centrabl. 2 1 : 23·28; 309·3 1 3 . CHOWDH URY, N .P . 1 937. Notes o n some I ndian species o f Lycopodium with remarks o n the

distribution of the genus i n I ndia. Trans. Nat. Inst. Sci. India, 1 : 1 87·226. GHATA K , J. 1 965. Some evidences of cytological evolution in Lycopodium L .S.L . The Nucleus,

8 (1) : 45·58. LOVE, A . and LOV E , D. 1 958 . Cytotaxonomy and classification of Lycopods. The Nucleus, 1 (1 J

: 1 · 1 0. P I C H I SERMOL L I , Rodolfo, E.G. 1 97 1 . Names and types of the genera of the fern-a l l ies :

L ycopod iaceae, Selagi nel laceae, I soetaceae, Equ isetaceae, Psi I otaceae, T me si pteridaceae . Webbia, 26(1) : 1 29·1 94 .

428 F E R N GAZETTE: V O L U M E 1 1 PART 6 ( 1 978)

SHOR T NOTES RANGE EXTENSION O F THE GENUS C I BOTI UM TO

NEW GUINEA The taxonomy and d istribution of the genus Cibotium Kaulfuss (Cyatheaceae) i n Malesia was revised by Holttum ( 1 963) . There are three species in the area : C. barometz ( L . ) J .Sm . ( N . E . I ndia to S . Ch ina and Formosa , south to Malay Peninsu la , Sumatra and Java) , C. cumingii Kunze (Ph i l ippines) and C. arachnoideum (C.Chr. ) Holttu m (Sumatra, Borneo ) . I n May 1 977 C. barometz was co l lected in eastern New Guinea, thus considerably extending the eastward range both of this species and of the genus. lt was an uncommon floor species on steep slopes in Lithocarpus/Castanopsis forest at 800 m on Oomsis ridge on the north side of . the Herzog Range, Moro be d istrict. Voucher specimens are lodged in the herbar ium of the Department of Botany, Divis ion of Forests, Lae, i n the R ijksherbar ium, Leiden and in the author's private herbar ium, no. 5962.

ACKNOWLEDGEMENTS

I wish to thank my husband , John Croxa l l , and David Symon and fami ly , for assistance in the f ie ld ; and Nigel C luny for organis ing this col lecting tr ip .

R E F ER ENCES

HOL TTU M , R . E . 1 963. Flora Malesiana Series 2 Vol . 1 part 2, Cyatheaceae, pp. 1 64-1 66.

B.S. PA R R IS, Botany School, Downing Street, Cambridge CB2 3EA.

NOTES ON SOIL TYPES ON A FERN-RI CH TROPI CAL MOUNTA I N SUM M I T I N MALAYA

Gunong U lu Ka l i is a forested mountain peak ( 1 0 1 ° 47.5' E, 3° 25 .7 ' N ;5,81 4 ft. (c. 1 772m ) ) i n the southern p_art of the Ma in Range of Pen insu lar Ma laysia, 20 m iles (c. 32.2 km ) N N E of Kuala Lumpur. Annual ra i nfa l l is estimated at 1 00 inches (c. 2500 mm) , with most of this fa l l ing between October and December ( Dale 1 960, 1 963, 1 964) . Dry, sunny mornings are usual ly fol lowed by mist or ra in , with temperatures frequently below 1 8° C.

The natural vegetation at around 5,000 feet is montane oak forest, nearing its upper l i m it, and growing in l i thosols, podsols and shal low yel low l atersols derived from the gran ite core of the mounta in (Panton 1 964) . Above this it a montane ericaceous forest, with scrub forest in very exposed s ituations (Wyatt-Smith 1 964, Burgess 1 969) . The f lora o f the summit and r idge is, however r ich in ferns, with over 1 00 species and varieties recorded, about half of wh ich are terrestria l (Piggott 1 97 7 ) .

Amongst the most commonly encountered ferns are Plagiogyria tuberculata Copel . and 8/echnum vestitum (B I . J Kuh n , which are abundant in the wetter areas of dwarf forest. Coryphopteris gymnopoda (Bak.) Holtt. and Acrophorus blumei Ching are common i n sheltered hol lows. Cyathea hymenodes M ett. and C. lurida (8 1 .) Cope l . are found along the r idge, a n d C. contaminans (Hook .) Cope l . in the l arger va l leys.

The recent opening of a hotel com plex near the summit, with access by road, has given opportun ity for so i l types and an exposed roadside soil prof i le to be exami ned. The paucity of such observations in l oca l ities so rich i n ferns has prompted the fol lowing brief observations to be recorded .

Surface so i l types consist chiefly of thick, fibrous root mats overly ing varying depths of peat. Both the soi l and the run-off water have proved to be very acidic. Two

SHORT NOTES 429

samples of orange-brown run-off water co l lected in steep montane ericaceous forest with abundant Pandanus, which were tested , gave pH readings of 4 . 1 0 and 4. 1 8 respectively . A sample o f dark-brown f ibrous root mat peat from a very exposed remnant of scrub forest on a ridge gave a f ie ld pH reading of 4.0 and consisted of 99.4% organ ic matter. A sample of dark-brown Sphagnum root-mat from scru b forest with Rhododendron and Nepenthes on a ridge gave a f ie ld pH reading of 3.90 and conta i ned 99. 1 % organic matter . A sample of dark chocolate-brown soi l obtained from a road cutting 0. 7 m i les (1 km) from the summit in montane ericaceou s forest w ith Pandanus and palms gave a field pH reading of 3.92 and contained 88.2% organ ic matter. A sample of medium-brown subso i l from the same locality gave a f ie ld pH read i ng of 4.30, a lthough the content of organ ic matter was <;m ly 1 1 .9%.

At this l atter station, the road cutt ing enabled a clear idea of the soil prof i l e to be obta i ned. From this it could be seen that only the top 2 inches (c. 5.0 cm) consisted of forest l itter . Below this, the dark-brown h ighly acidic fibrous peat formed an 8-inch (c. 20 cm) th ick layer, over ly ing the acid ic sandy loam, wh ich formed a layer 1 4 inches (c. 35.5 cm ) deep. The bottom of this layer fol lowed the contour of an approx imately 1 inch (c. 2.5 cm) th ick red-brown i ron-sta ined layer of compact weathered rock , immed iately overlying the bedrock, which is granitic.

Analysis of the bedrock showed it to consist of about 80% free quartz and about 20% ferromagnesian compounds.

The soi l s and run-off near the su mmit of this mounta in are clearly strongly acid ic, and compare with, a lthough are even more acidic than, those reported at a s imi lar alt itude (5,250 ft. (c. 1 600 m ) ) by Dames ( 1 955) i n East Central Java.

ACKNOWLEDGEM ENT

Ana lyses quoted were carried out by Chemara Research Station , Seremban, Malaysia.

R E F E R E NCES

BURG ESS, P.F. ( 1 969) Ecological factors in hi l l and mounta i n forests of the States of Malaya. Mal. Nat. J. 22: 1 1 9-1 28.

DA LE, W . L . ( 1 960) Rainfal l of Malaya, I & 1 1 . J. Trap. Geog. 13: 23-37 and 14: 1 1 -28. DA LE, W . L . ( 1 963) Surface Temperatures in Malaya . J. Trap. Geog. 1 7: 57-7 1 . DA LE, W . L . ( 1 964) Sunsh ine in Malaya . J. Trap. Geog. 19: 20-26. DAM ES, T.W.G . ( 1 955) Soils of East Central Java. No. 1 41 , General Agricultural Research

Station, Bogor. PANTO N . W.P. ( 1 964) The 1 962 Soil Map of Malaya. J. Trap. Geog. 18: 1 1 8-1 24. P I GGOTT, A.G. ( 1977) The Ferns of G u nong Ulu Kal i. Gard. Bull. Sing. 30 1 :31-43 WY A TT-SM ITH, J . ( 1 964) Pre l iminary Vegetation Map of Malaya with Descr iptions of Vegetative

Types. J. Trap. Geog. 18: 200-2 1 3 .

A.G. P I GGOTT, 21 Jalan Data Klana, Seremban, Malaysia.

ISOETES IN RAJASTHAN, IND I A

lsoetes i s known, so far, from Mt. Abu in south west Rajasthan ( M ita I , 1 969 ) a nd Atru, Kota in south east Rajasthan (Gena et al., 1 976) . We now record its occurrence about 1 75 km away north of the latter local ity . A luxu riant patch spread over an area of approximate ly 500 sq ft was observed by one of us (SM) in Novem ber 1 975 near Dausa, Jaipur a long the Dausa-Rajgarh Road . The plants were growing along the margi n of rain water co llected in a wide depression beside the road near the 5 km

430 F E R N G AZETTE: VOLUME 1 1 PART 6 ( 1978)

stone. This lsoetes was found to resemble the bigger form from Atru in habit, size of plants and the ornamentation of megaspore wal l . However, the rh izomorph here invariably conta ins 3 lobes as against the equal frequency of 2 and 3 l obed rhizomorphs of Atru materia l . M ore important the elongated megasporangia in thi s form conta in fused megaspores frequently a n d are of four types. The circular megasporangia of the Atru mater ia l i n contrast rarely contai n fused megaspores and are trimorph ic. Although at Atru a smal ler form of lsoetes a l so occurs i ntermixed with the bigger form . (Gena et al. , 1 976) we found no other form at Dausa, though the local ity was v is ited again in June 1 976 d uring the dry spell to ascertain if there is any late a ppearing smaller form ( cf I. coromandeliana, I. indica and I. panchananii; Pant & Srivastava, 1 962) . Thus Rajasthan state may conta i n four d ifferent taxa of lsoetes - a bigger form at Dausa, a smaller form at Mt. Abu and i ntermixed bigger and smal ler forms at Atru . The cyto-taxonomy of a l l these taxa is currently being studied.

R E F E R ENCES

GENA, C.B., MITAL, P L . & BHAR DWAJA, T .N . 1 976. lsoetes i n flajasthan. J. Bombay nat. Hist . . Soc. 73: 559-562.

MITAL, P.L. 1 96![ Ferns and Fern-allies of Rajasthan . J. Bombay nac. Hist. Soc. 66 91-42.

PANT, D.D. & S R I VASTAVA. G .K. 1 962. Genus lsoetes in I ndia. Prov. Nat. Inst. Sci. India, 28: 242·280.

S. M ISRA, University of Rajasthan, Jaipur, India.

T. N. B HA RDWAJA, Government College, Ajmer, India.

PAR IS H E R BAR I UM PTE R I DOPHYTES The l arge and i m portant col lections of Pteridophytes in the herbar ium of the

Museum d'H istoire Nature l le , Paris, have recently been reorgan ised from an a lphabetical sequence to the generic sequence of Crabbe, Jermy and M i ckel ( 1 975) . which has made it more easy to f ind types and other i mportant specimens.

Pteridologist a re welcome to vis it the herbarium and are requested to write i n advance to the D i rector, 1 6 rue d e Button 75005 Paris, France. The col lection i s under the supervis ion of Mr F . Badrll.

R EF E R ENCES

CRABBE, J.A., JERMY, A.C. & M ICKEL, J.T. 1 975. A new generic sequence for the pteridophyte herbarium. Fern Gaz. 1 1: 141- 162.

F. BAD R E . Museum National D'Historie Nature/le, Paris