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Week 4; Monday

Announcements: First lecture exam on Friday; Review session Wednesday at 5:30 Lecture: Rosidae s.l., continued Aceraceae - Maple family (2 gen/113 spp) Aceraceae are included in Sapindaceae in textbook, so be sure to note the

restricted circumscription that we use in this class. 1) woody trees or shrubs 2) leaves opposite Mnemonic for remembering opposite leaved woody plants A MAD Cap Horse --> Adoxaceae, Maple, Ash, Dogwood, Caprifoliaceae, Horse

chestnut. - typically palmate venation; usually simple, sometimes palmately compound (pinnately compound in Sapindaceae s.s.) 3) Flowers:

- 4-5 parted - nectary disk - formed in staminal whorls - flowers bisexual or unisexual, if the latter, then plants either mono- or dioecious,

or androdioecious (some plants with perfect flowers, some plants with male flowers only; example Mountain maple – A. glabrum)

- may be insect or wind pollinated - fruit of 2 fused carpels each with pronounced wing and dispersed by wind

“samaroid schizocarp” Floral formula: * 4-5, 4-5, 4-10, 2, samaroid schizocarp [carpels fused] The family Aceraceae now is included in a larger family, Sapindaceae, which is a

paraphyletic ancestral group. The Sapindaceae largely is tropical and has more variation in floral morphology. This expanded family also includes the Hippocastanaceae, the Horse Chestnut or Buckeye family.

Aceraceae and Hippocastanaceae both are monophyletic, but by recognizing those families as distinct from the traditional Sapindaceae, the Sapindaceae may be paraphyletic. So, the solution adopted by the textbook is to include them all in one family, Sapindaceae. The name “Sapindaceae” is used for the larger group, because it was used as a family name before either of the others.

see overheads

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Brassicaceae Mustard family (419 gen/4130 spp) Also called “Cruciferae” - one of ten families that has two accepted names - This family gets its traditional name from the ‘cross-shaped’ petal arrangement. - many economically important plants. e.g., Brassica oleracea - the following are “cultivars” maintained by artificial

selection: var. capitata - cabbage var. gemmifera - brussels sprouts var. acephala - kale

var. botritus - cauliflower var. italica - broccoli

1) herbaceous 2) Glucosinolates – secondary chemicals stored in plant vacuoles. These are

released from the vacuole when damage occurs to the cell (e.g., from insects chewing on the leaf) and are altered by the enzyme myrosinase to produce compounds called isothiocyanates (“mustard oils”). Mustard oils give characteristic smell and taste; probably serve as deterrent to herbivory in nature.

- overheads from Rodman et al. on glucosinolates 3) Flowers - VERY uniform in floral structure;: - 4-parted actinomorphic calyx and corolla, --> often cruciform in traditional

Brassicaceae senus stricto - Stamens 6 (or many) often Tetradynamous, 4 + 2 stamen arrangement (4 long

inner and 2 short outer) in traditional Brassicaceae s.s. - carpels two, fused, ovary superior with a ‘replum’ (term for a false septum with

thickened marginal rim, specific to this family), separating the two locules; ovules attached parietally to margins of replum.

- Fruits typically a capsule called either a silicle (<2X longer than wide) or silique (>2X longer than wide), Illustration:

silicle silique

Floral formula: * 4, 4, 2+4 (6), 2, silicle or silique [carpels fused] The traditional Brassicaceae, which include almost all of our species, are

monophyletic, but nested within the paraphyletic Capparaceae (as with the Aceraceae in Sapindaceae).

The Capparaceae typically have 4-parted calyx and corolla, with 6 equal-length stamens (not in 4+2 arrangement), but sometimes have more or fewer numbers of parts. Also fruit types are different – see overhead (Rodman et al. 1998)

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Short piece on Draba in Sand County Almanac? – insufficient time in this lecture to read.

Onagraceae - Evening Primrose family (16 gen/650 spp) This small family is particularly prominent in the western USA and includes evening

primroses, Clarkia, fireweed, etc. 1) herbaceous 2) leaf arrangement variable (alternate, opposite or whorled) 3) Flowers: - bisexual - parts in 4’s (except Circaea, which is native to the PNW) - anthers versatile - which means attached by a thin connective allowing them to

dangle loosely - pollen usually in tetrads (four grains that don’t separate); attached by viscin

threads - ovary inferior; axile placentation - fruit a capsule (dry dehiscent)

Floral formula: * 4, 4, 4 or 8, 4 capsule [carpels fused; inferior ovary] A good monophyletic family not threatened with extinction due to inclusion in

another group!

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Week 4; Wednesday Announcements: First Lecture Exam next Friday; review on Wed at 5:30 here.

Lecture: Continuing in Rosidae s.l.... Three of the four families (Violaceae, Salicaceae, and Malvaceae) we will examine

today, along with one we examined on Monday (Brassicaceae) were placed previously in the Subclass Dilleniidae (e.g., in Cronquist 1981 and Takhtajan 1987). We now know that the Dilleniidae is not a ‘natural’ or monophyletic group and families once assigned to that group belong in other groups, including Caryophyllids, Rosidae, and Asteridae.

Salicaceae - willow, poplar family (2 gen/485 spp)

Salix – willows; Populus – poplars, cottonwoods, aspen Salicaceae has been expanded dramatically to include most of Flacourtiaceae, a

primarily tropical family with much more diverse morphology. Salicaceae as covered here is monophyletic and is nested within Flacourtiaceae (hence Flacourtiaceae would be paraphyletic). OVERHEAD

1) shrubs and trees Vegetative reproduction by root sprouts (e.g., aspen groves) or rooting of branches

(e.g.,willows along streams) is common. The largest single living ‘organism’ is an aspen grove in Utah (Populus tremuloides)

2) lvs simple, serrate with ‘salicoid teeth’ (vein ending at tip of tooth with a small gland)

3) Dioecious - separate male and female plants 3) Flowers in catkins (both male and female) – pussy willows - fls borne in axil of hairy bracts on catkin-like axis (not always pendent) - no perianth (a nectar gland or cup-like bract may be interpreted as calyx) - ovary superior, with 2-4 fused carpels with many ovules (different from oaks and

birches, which are inferior and with 1-few ovules) – fruit a capsule 4) seeds hairy - hence “cottonwood” Floral formulae: female: * 0, 0, 0, 2-4 capsule [carpels fused] male: * 0, 0, 2-∞, 0

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Violaceae - violet family (22 gen/950 spp) 1) mostly tropical trees(!); herbs in temperate zone 2) lvs simple (often cordate at base in violets) 3) Flowers zygomorphic (bilaterally symmetric) - petals 5, the lower one forming a ‘spur’ - stamens five, the lower two forming a nectary (held within the petal spur) - ovary superior; placentation parietal; 3 fused carpels – fruit a capsule Floral formula: X 5, 5, 5, 3 capsule [carpels fused] Violets often have two different kinds of flowers on the same plant: 1) Chasmogamous - large showy flowers that typically are cross-pollinated 2) Cleistogamous - small inconspicuous flowers that don’t open and are self-

pollinated in the bud Both of these represent sexual reproduction, but one typically outcrosses and the

other typically self-fertilizes. Malvaceae - Mallow family cotton, okra, Hibiscus, cacao (204 gen/2330 spp) 1) mostly herbs in North America; also shrubs and trees 2) lvs simple, palmately veined, often lobed or compound 3) Stellate or branched hairs 4) Mucilaginous cells (e.g., makes okra ‘slimy’) 5) Flowers: - 5 parted - stamens (5-) many, often +/- fused by the filaments into one or more clusters;

when connate at the filaments to form a tube around the style then called monadelphous

- pollen highly ornamented, spiny - ovary superior; placentation axile, carpels usually 5 (sometimes 2 or many) Floral formula: * 5, 5, (5-)∞, 5 (2-∞) capsule (schizocarp + nut, too) [filaments

connate] [carpels fused] cotton - Gossypium hirsutum - from S. America is a tetraploid resulting from a

hybridization between an old world (African) and a New World (S. American) species!

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Saxifragaceae - saxifrage family (30 gen/550 spp) This family has a rather basic floral formula for the Rosidae and other higher dicot

groups. Perhaps due to this reason, it has consisted of a very heterogenous collection of plants. Research by scientists at WSU (Soltis et al.) have shown that many of the group belong elsewhere in the Tricolpates and that the Saxifragaceae sensu stricto contains only the herbaceous plants centered in the western USA.

OVERHEAD 1) herbaceous 2) leaves simple, often palmate and serrate; often forming basal rosette 3) Flowers -

- actinomorphic (rarely zygomorphic, e.g., Tolmeia) - sepals and petals in 5s, often attached to a cup-shaped or flared hypanthium - stamens 5 or 10 - carpels 2-3 usually only partially connate at base - Ovary may be superior, half inferior, or inferior (depending on degree of fusion of

hypanthium to ovary wall). ___ Floral formula * 5, 5, 5 or 10, 2-3 capsule (berry) [Carpels fused; ovary position

various]