Garden Plants that are Known to Become Serious Coastal Weeds

SOUTH AUSTRALIAN COAST PROTECTION BOARD No 34 September 2003

coastline

GARDEN PLANTS THAT HAVE BECOMESERIOUS COASTAL WEEDSSadly, our beautiful coastal environment is under threatfrom plants that are escaping from gardens andbecoming serious coastal weeds. Garden escapeesaccount for some of the most damaging environmentalweeds in Australia. Weeds are a major environmentalproblem facing our coastline, threatening biodiversityand the preservation of native flora and fauna. Thisedition of Coastline addresses a selection of commongarden plants that are having significant impacts on ourcoastal bushland.

WHAT ARE WEEDS?Weeds are plants that grow where they are not wanted.In bushland they out compete native plants that are thenexcluded from their habitat. Weeds are not always fromoverseas but also include native plants from otherregions in Australia.

WEEDS INVADE OUR COASTLINE…Unfortunately, introduced species form a significantproportion of coastal vegetation in South Australia. Arecent biological survey of South Australian coastaldune and cliff top plant habitats (Oppermann 1999)revealed that 38% of the surveyed coastal plants wereintroduced species. In contrast, only 27% of plantspecies are introduced in non-coastal parts of the state.The higher proportion can be partly attributed to closesettlement along the coast, and escapes fromresidential gardens into coastal environments. Inextreme cases, the number of introduced species is evenhigher than the latter. For example, an extensive studyof vegetation at Tennyson Dunes in metropolitanAdelaide found that 57% of the species were introduced(Tennyson Dune Care Group). This alarming figurehighlights the urgency of the need to control weedsalong our coastline.

THE IMPACT ON OUR COASTALENVIRONMENTWeeds that are successful in the coastal environmenthave often originated from regions with a similar climateto Australia, such as the Mediterranean and SouthAfrica. Introduced species often have an advantage overlocal native plants, through fast growth rates and a lackof pests or diseases that control them in their naturalenvironment.

The ability of weeds to spread and establish allows themto readily invade and displace native plant communities.

Vegetation communities that originally had a diversestructure are transformed to a simplified state whereone or several weeds dominate. Weeds aggressivelycompete with native species for resources such assunlight, nutrients, space, water, and pollinators. Theregeneration of native plants is inhibited once weeds areestablished, causing biodiversity to be reduced.

Furthermore, native animals and insects are significantlyaffected by the loss of indigenous plants which they relyon for food, breeding and shelter. They are also affectedby exotic animals that prosper in response to alteredconditions.

Weeds require costly management programs and divertresources from other coastal issues. They can modifythe soil and significantly alter dune landscapes.

HOW ARE WEEDS INTRODUCED ANDSPREAD?Weeds are introduced into the natural environment in avariety of ways. They can be accidentally introduced bythe movement of seed contaminated soil, or deliberatelyfor agricultural, horticultural and utility purposes.

Weeds can reproduce and spread readily from theiroriginal point of introduction to invade other coastal andinland environments. They are primarily spread byseeds that can be dispersed by wind, water, animals andhumans. Seeds also become attached to the fur or feetof animals. Humans help to disperse seeds whichbecome attached to clothing, footwear, machinery, or bythe movement of seed contaminated soil. Weeds canoften also reproduce vegetatively; this occurs whensegments of stems break off and take root to form a newplant. These weeds require careful disposal, asindividual pieces can take root and grow for severalmonths after breaking off from the parent plant - even ifthey are not on soil or sand.

WHAT CAN YOU DO TO HELP? It is important to make informed choices when selectingplants for coastal gardens. Avoid purchasing invasiveplants and remove invasive species from your garden.If you see a plant for sale that is a potential weed bringit to the attention of nursery staff. Plant native speciesfrom your local area that are naturally suited to coastalconditions. This will increase habitat for native plantsand animals, maintain the gene pool and thereby ensurethe survival of local species. Reduce the damage causedby weeds, and protect our beautiful coastal environmentand its biodiversity…Before it’s too late!

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SCIENTIFIC NAMEAgave americana

COMMON NAMESCentury plant, Maguey, American Aloe

WHAT DOES IT LOOK LIKE?Century plant is a giant succulent. Leaves are 2m inlength, grey, and variegated with yellow or cream.Leaves are thick and prickly around the edge, forming arosette at the base. Flowers are 70-85mm long, paleyellow and fleshy with a large stalk growing 7-10m inheight. Flowers are evident December through toFebruary.

HOW DOES IT EFFECT THE ENVIRONMENT?Century plant is invasive in coastal environments,forming a dense groundcover that suppresses nativevegetation. It also creates conditions that are favourableto exotic fauna. For example, it provides protection forrabbits and is a source of food and water for themduring the summer months when they feed on the

succulent new rhizomes. Century plant alsosignificantly decreases the visual amenity of an area.

HOW DOES IT SPREAD?Dispersal is primarily by seed and vegetativereproduction.

HABITATIt inhabits rocky hillsides and coastal dunes where it wascommonly planted by farmers in the past.

WHERE IS IT FROM?Its country of origin is unknown, but it can be foundgrowing wild in Mexico.

DISTRIBUTIONThe distribution of century plant is limited within SouthAustralia.

DON’T CONFUSE IT WITH…It is a distinctive plant not easily mistaken with nativespecies.

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Port Clinton

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SCIENTIFIC NAMEArctotis stoechadifolia

COMMON NAMESArctotis, African daisy, Aurora daisy, White Arctotis

WHAT DOES IT LOOK LIKE?This perennial is a ground cover plant that growslaterally in dense clumps. Leaves are grey to green anddivided with indented margins. Flower heads up to 10cmacross are produced from late spring to early summer.The flower centre is blue, with white, cream, pink,bronze or blue petals.

HOW DOES IT EFFECT THE ENVIRONMENT?Arctotis significantly alters the coastal environment bysmothering native groundcover species and low shrubs.The growth of native seedlings and mature native shrubsis also suppressed and in time the vegetation structurewill change as plants become senescent and are unableto regenerate. This process leads to a reduction innatural diversity, as indigenous plant species arereplaced with a dense monoculture of Arctotis. Thenatural processes associated with dune formation arealso altered, causing dunes to have steeper rather thangentler angled slopes.

HOW DOES IT SPREAD?Dispersal is by seed.

HABITATArctotis grows wild in the drier parts of South Africa.

WHERE IS IT FROM?South Africa.

DISTRIBUTIONFound growing around nearly all townships andsettlements along South Australia’s coast due to its useas a garden plant.

DON’T CONFUSE IT WITH…It is a distinctive plant not easily mistaken with nativespecies.

Tennyson

Semaphore Park

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SCIENTIFIC NAMEArgyranthemum frutescens

COMMON NAMEMarguerite daisy

WHAT DOES IT LOOK LIKE?Marguerite daisy is a shrubby daisy to knee high.Leaves are light green, fleshy and deeply lobed. Theflower is a small white daisy to 3cm. The yellow centreof each flower contains many seeds. Flowering occursbetween spring and summer.

HOW DOES IT EFFECT THE ENVIRONMENT?It is very invasive in dunal areas where disturbance hasoccurred. Marguerite daisy is usually found in the mid-dune where it invades areas that are degraded or in theprocess of being degraded. It competes aggressivelywith native flora that is less vigorous.

HOW DOES IT SPREAD?Seed production is prolific and is the primary means ofdispersal.

HABITATMarguerite daisy often occur in sunny positions in sandalong clifftops and in dunes.

WHERE IS IT FROM?Canary Islands

DISTRIBUTIONMarguerite daisy occurs in the southern higher rainfallzones from Eyre Peninsula to the South East.

DON’T CONFUSE IT WITH…Marguerite daisy seedlings can be confused withVariable Groundsel (Senecio lautus) seedlings. Asmature plants they are quite different as VariableGroundsel has yellow flowers, not white.

Semaphore Park

Beachport

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SCIENTIFIC NAMECarpobrotus edulis - yellow flower

COMMON NAMESPigface, Hottentot fig, Ice plant, Highway ice plant

WHAT DOES IT LOOK LIKE?Pigface is a ground running perennial that forms densemats. Each plant can grow up to 40-55cm thick and 8-10m wide. Leaves are 6-10cm long, 5-12mm wide anddull green with a reddish tinge. Stems grow on or justbelow the surface. Flowers have numerous petals andstamens that reach up to 8cm in diameter. Flowers areyellow at first and gradually change to pink with age. Theflowering period extends from late summer to winter.Fruits are to 20mm in diameter, globular and ranges fromdull yellow to red-purple.

HOW DOES IT EFFECT THE ENVIRONMENT?Introduced Pigface (Carpobrotus edulis) is a threat tonative vegetation. A concern is that Carpobrotus edulismay be hybridising with the native Carpobrotus rossii,reducing its genetic purity. It invades and displacesnative plant communities by forming dense mats thatcover the ground, smothering native species anddestroying coastal habitat in its path. The growth ofnative seedlings and mature native shrubs is alsosuppressed. Introduced Pigface is a hardy plant that canresist herbivores and rigorous competition.

Introduced Pigface has indirect impacts on theenvironment. It predominately invades sandy areasalong the coast. Native Pigface is an important stabiliser.Introduced Pigface causes sand dunes to becomestabilised, but significantly reduces the biologicaldiversity of dune vegetation. The native is not asaggressive and occurs as an open, isolated plantwhereas introduced pigface forms dense mats.

HOW DOES IT SPREAD?Pigface is spread both vegetatively and by seeds.Vegetative reproduction is when segments of leaves andstems break off from the parent plant and take root toform a new plant. Vegetative reproduction is essential tosurvival in coastal areas, where vegetation is frequentlyburied by sand. Pigface spreads rapidly by vegetativereproduction once established, with individual segmentsgrowing up to 1m per year. Seeds are another form ofdispersal. Fruits are produced in summer and containhundreds of seeds. Seeds are dispersed when birds andmammals eat the mature fruits.

HABITATPigface inhabits coastal areas of South Africa.

WHERE IS IT FROM?Cape Region of South Africa.

DISTRIBUTIONIntroduced Pigface is widespread in southern Australia,extending throughout the coastal regions of EyrePeninsula, Yorke Peninsula, Northern Lofty, Murray andSouth East.

DON’T CONFUSE IT WITH…Introduced Pigface is similar to the native Karkalla(Carpobrotus rossii). The introduced Pigface isdistinguishable from this species as it has yellow daisy-like flowers, whereas the native Carpobrotus rossii haspink flowers with a white base.

Angular pigface (Carpobrotus aequilaterus) is anotherspecies that has been introduced from South America. Ithas similar impacts on the environment to Carpobrotusedulis, and may also be hybridising with the nativeKarkalla (Carpobrotus rossii). Angular pigface is similarin appearance to the native Karkalla. However, AngularPigface is easily distinguished from Karkalla as it is largerwith purple flowers and a yellow to pink centre.

Beachport

Native Pigface

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SCIENTIFIC NAMECoprosma repens

COMMON NAMESMirror plant, Mirror bush, Taupata plant, Looking-glassbush, Marble plant.

WHAT DOES IT LOOK LIKE?Mirror bush is a multi stemmed shrub growing to 2-4mhigh. Leaves are 2-8cm long, slightly fleshy, dark green,round and very glossy. Flowers are small, greenishwhite and arranged in clusters. Flowers are produced insummer. An interesting feature is that flowers areunisexual, meaning female and male bushes areseparate. Bushes with female flowers producetranslucent fleshy orange-red berries in autumn andwinter. Berries grow to 1cm in width.

HOW DOES IT EFFECT THE ENVIRONMENT?Often invades coastal environments where it can castdense shade that inhibits and suppresses nativevegetation. Natural diversity is reduced through habitatdegradation and as a result of an altered vegetationcommunity composition.

HOW DOES IT SPREAD?Mirror bush produces many seeds that are dispersed bybirds and other animals attracted by the bright orange-red berries. Seeds are also spread by contaminated soil.Seeds commonly germinate under light shade or wherethe ground is disturbed.

HABITATIt is recorded as a coastal cliff plant in New Zealand, butcan be found in rocky and sandy coastal habitats inAustralia in both open and forested areas. It prefers highrainfall. Due to the adaptability of this species it willbecome more widespread over time.

WHERE IS IT FROM?New Zealand. It was introduced to Australia as a hedgeplant during early European settlement.

DISTRIBUTIONAll high rainfall parts of SA’s coast.

DON’T CONFUSE IT WITH…Coprosma is a distinctive spreading shrub that is noteasily mistaken with native species.

Glenelg

Semaphore Park

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SCIENTIFIC NAMEDipogon lignosus

COMMON NAMESLavatory creeper, Dolichos pea, Mile a minute, Dipogon,Okie bean, Australian pea.

WHAT DOES IT LOOK LIKE?Lavatory creeper is a perennial large woody vine.Leaves are 1-7cm long, bright green and egg shapedwith a thin texture. Pink, white or mauve pea-likeflowers are arranged in clusters, with each flower beingup to 1.5cm in size. Flowers are followed by flat, pea-like pods. Flowers produced in spring. Stems grow to3cm long. Fruit is 2.5-5cm long.

HOW DOES IT EFFECT THE ENVIRONMENT?Lavatory creeper is a rampant species that readilyestablishes in disturbed areas. It spreads over theground and climbs shrubs and trees, smotheringexisting native species creating denser canopies,reducing light penetration and preventing regeneration.Lavatory creeper belongs to the Leguminosae family andcan therefore fix nitrogen. Nitrogen fixation leads to anincrease in soil fertility in an environment that normallyhas low nutrient soils. Subsequently, this encouragesgrowth of other weeds that would not otherwise be ableto establish in the dune environment. Lavatory creeperis considered a threat wherever it has escaped intonative habitat.

HOW DOES IT SPREAD?Lavatory creeper spreads by seed or rhizomes(underground stem). Seeds are explosively ejected frompods over several metres. Seeds are viable for manyyears, and germination may be initiated by disturbanceor fire. Lavatory creeper is also spread through gardenrefuse and contaminated soil.

HABITATMoist shady sites associated with forests and tallshrublands.

WHERE IS IT FROM?Western and Eastern Cape, South Africa

DISTRIBUTIONThroughout thewetter parts ofSouth Australia andin particular thesettled areas. It isalso found inWestern Australia,Queensland, NewSouth Wales andVictoria.

DON’T CONFUSE ITWITH…It is a distinctivecreeper not easilymistaken with nativespecies.

OTHERIt is essentially anold-world gardenescapee and cantherefore be found

near settlement and abandoned farmhouses oroutbuildings. Lavatory creeper was often used toobscure the outside toilet or chookhouse.

Robe

Robe

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SCIENTIFIC NAMEGazania sp.

COMMON NAMEGazania

WHAT DOES IT LOOK LIKE?Gazania rigens is a many branched spreading perennialherb. It spreads along the ground and can reach up to30cm in height. Leaves are 4-10cm long, slender, witha leathery green surface. Fine white hairs are evident onthe underside of each leaf, giving it a woolly texture.Daisy-like flowers are 5-8cm in diameter. Solitaryflowers are produced on long stalks (peduncles) and areusually orange to yellow in colour. Flowering occursthroughout the year, but mainly in spring and autumn.

Gazania linearis is a clump forming perennial growing to10cm in height. This is different to Gazania rigens thatis spreading in habit. Leaves are small, linear and darkgreen with a white under surface. Flowers up to 10cmacross are produced in spring. Flowers range fromyellow to orange, with a black to dark purple markingnear the base of each petal.

HOW DOES IT EFFECT THE ENVIRONMENT?It usually invades dunes and headlands in sunny andexposed conditions. Gazania is readily established insandy environments where it severely alters thevegetation community structure by suppressing nativeplants. An integrated approach is required to eradicatethis species from coastal environments, as it is oftenreintroduced into managed areas by the continuedplanting in residential gardens and informal plantings incoastal dunes to stabilise sand areas in front ofresidences.

HOW DOES IT SPREAD?Gazania is predominantly spread by seed and as a resultof deliberate plantings in gardens. It can also spreadvegetatively by stolons (creeping stems) that take rootand form new plants.

HABITATGazania inhabits coastal areas, particularly in exposedand sunny positions.

WHERE IS IT FROM?Gazania is native to the alpine meadows of tropicalSouth Africa.

DISTRIBUTIONYorke Peninsula, Eyre Peninsula, Southern Lofty Region,South East, top of Spencers Gulf coast and around StVincent Gulf and the Southern Fleurieu coastline. It isalso found growing around nearly all townships andsettlements along South Australia’s coast due to itspopularity as a garden plant. Gazania linearis presentlycovers a significant proportion of degraded areas withinthe Southern Fleurieu Dunes, parts of Yorke Peninsulaand the Murray flats.

DON’T CONFUSE IT WITH…Gazania is a distinctive low growing plant not easilymistaken with native species.

Henley Beach

Henley Beach

Grange

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SCIENTIFIC NAMELeptospermum laevigatum

COMMON NAMESCoastal tea-tree, Victorian tea-tree, Coast tea-tree,Australian myrtle

WHAT DOES IT LOOK LIKE?Coastal tea-tree is a large shrub or small tree growing to4m in height. Leaves are to 2cm long, broad, flat, andblue-green to grey. Leaves are aromatic, producing astrong smell of eucalyptus oil when crushed (Coastaltea-tree belongs to the eucalypt family Myrtaceae).Flowers are 15-20mm in diameter, with 5 white petalsand numerous stamens arranged around the rim.Flowering occurs from late winter to spring. Fruits are aflat-topped, cup shaped capsule 7-8mm across. Fruitscontain 8-12 valves that release lots of slender seedswhen opened. The trunk is short, thick and crooked.

HOW DOES IT EFFECT THE ENVIRONMENT?Coastal tea-tree invades disturbed areas, coastal heathsand bushland. It significantly alters the naturalenvironment by forming dense thickets that eliminateother plants through shading and competition forresources such as water, soil and nutrients. This is ofparticular concern to biodiversity, as indigenous plant

species can be replaced with a dense monoculture ofCoastal tea-tree. This also then dramatically alters thehabitat for native fauna.

HOW DOES IT SPREAD?Dispersal is primarily through wind-blown seed, waterand deliberate plantings. It can also be spread by seeddehiscing from dying branches holding fruit and thedeath of whole trees due to fire or old age.

HABITATCoastal tea-tree largely inhabits coastal dunes,headlands and scrubs where conditions are harsh andwindswept. It is predominantly found on dunes andheadlands, and in areas that are in close proximity to thecoast.

WHERE IS IT FROM?New South Wales, Victoria and Tasmania. Recorded onGranite Island by early settlers but may have beenintroduced by whalers.

DISTRIBUTIONThe distribution of Coastal tea-tree was limited prior toEuropean settlement. Due to the disturbance of coastalhabitats since then, it is now found in coastal areas inSouth Australia, Victoria, Western Australia, Queenslandand Tasmania. Coastal tea-tree grows extensively onsandy soils in southern Australia.

DON’T CONFUSE IT WITH…Coastal tea-tree may be confused with the Desert tea-tree (Leptospermum coriaceum) which can inhabit nearcoastal areas containing red sands. Coastal tea-tree hasa round or obtuse leaf apex whereas the Desert tea-treehas small acute points to its leaves and is generally asmaller greener shrub.

Victor HarborRon Taylor

Henley Beach

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SCIENTIFIC NAMEPennisetum setaceum

COMMON NAMESFountain grass, Crimson fountain grass

WHAT DOES IT LOOK LIKE?It is a coarse perennial grass to 90cm in height.Fountain grass is densely clumped with erect stems.Leaf blades grow to 20-65cm long and 2-3.5mm wide.The leaf sheath is smooth. Fountain grass producesmany small, light pink to purple flowers from Januarythrough to April. Flowerheads are prominent, featheryand nodding.

HOW DOES IT EFFECT THE ENVIRONMENT?Fountain grass forms thick infestations that interfere withthe regeneration and survival of native plant species. Aless obvious impact is that Fountain grass raises theamount of organic material in an area, thereby increasingthe spread and intensity of fire. Native coastal shrublandspecies adapted to less extensive fire regimes areseverely affected. Fountain grass is well adapted to fireand will often regenerate prolifically after being burnt.

HOW DOES IT SPREAD?Vehicles, people and livestock are the primary method ofdispersal. However, seeds can be dispersed over shortdistances by wind, water, birds and fire. Its popularityas a garden ornamental has also contributed to itsspread. Seeds remain viable in the soil for at least 7years.

HABITATThis species is very adaptable and will occupy frontlinecoastal cliffs as well as inland disturbed roadsides.

WHERE IS IT FROM?Native to East Africa and the Middle East.

DISTRIBUTIONIt is rapidly increasing its distribution along main roadsin Southern Lofty, Northern Lofty and Eyre Peninsula. Itis found in small pockets on the face of low cliffs nearMarino and Hallett Cove.

DON’T CONFUSE IT WITH…It is a distinctive grass not easily mistaken with nativespecies.

Henley Beach

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SCIENTIFIC NAMEPolygala myrtifolia

COMMON NAMESMyrtle-leaved Milkwort, Bloukappies, Parrot Bush,Myrtle-leaf Milkwort, Butterfly bush, Myrtle-leavedMilkweed, Bellarine pea, September bush

WHAT DOES IT LOOK LIKE?Myrtle-leaved Milkwort is a densely leaved evergreenshrub usually 1-2m, but can reach up to 5m in height.Leaves are 1-4cm long, dark green and elliptical inshape. Leaf tips are either smooth or blunt. Flowers arepea-like, with the shape bearing resemblance to abutterfly. Flowers are purple to pale lilac in colour andclustered near the tips of branches. The lowest petal hasa brush-like crest that is forward pointing. A tuft ofbristles is present on the end of one petal. Purple veinsare visible in spring. The main flowering period isbetween September and October, but flowers are oftenevident throughout the year. Fruits are green at first,with flattened, heart-shaped pods. Two hard, dark brownseeds are released from a capsule when ripe. Matureseeds have a papery texture.

HOW DOES IT EFFECT THE ENVIRONMENT?Myrtle-leaved Milkwort readily invades undisturbedindigenous coastal vegetation and also readilyestablishes in areas where disturbance has occurred.This results in a loss of local native flora and faunathrough competition for resources. It has been knownto dominate the understorey in bush and coastalwoodlands.

HOW DOES IT SPREAD?Readily regenerates by seed. Myrtle-leaved Milkwort isoften spread by seed into coastal sand dune and cliffvegetation by birds, water and ants. Germination can bestimulated by disturbance or fire. Seeds remain viablefor at least three years.

HABITATResilient to coastal conditions; Myrtle-leaved Milkworttolerates poor soil, dry conditions, and exposure to salt.

WHERE IS IT FROM?Southern South Africa

DISTRIBUTIONMyrtle-leaved Milkwort is found in the higher rainfallareas of coastal South Australia from southern EyrePeninsula to the South East. It is also established alongthe coast of New South Wales, Victoria, WesternAustralia and Tasmania.

DON’T CONFUSE IT WITH…Myrtle-leaved Milkwort may be confused with the nativeSea box (Alyxia buxifolia) which has white flowers andred berries. Christmas Bush (Bursaria spinosa) hassimilar dark green foliage.

OTHERA sterile variety has been developed for the nurserytrade. For certainty purchase this plant only from areputable nursery.

Whalers Way Beachport

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SCIENTIFIC NAMERhamnus alaternus

COMMON NAMESBuckthorn, Italian Buckthorn, Blow-fly bush,Mediterranean buckthorn

WHAT DOES IT LOOK LIKE?Buckthorn is a large evergreen shrub or small tree to 5min height. It is densely branched with many leaves fromground level. Leaves are 2-7.5cm long, dark green, oval,with a pointed tip and lightly serrated edges. Leaveshave a leathery texture and are paler on the underside.Leaves are situated on alternate sides of the stem.Shoots are angular, covered with fine hairs, and oftenpurple when young. Flowers are small, pale green,scented, have 5 petals and are arranged in a cluster onsmall spikes along the stem. Male and female sectionsoccur separately on each flower; the male part issituated at the base and the top part is bisexual. The toppart flowers from August to September and then formsberries. Berries are 7mm long, glossy, firm, smooth andsmaller than a pea. Berries are green at first, red, andthen turn black when ripe. They contain a stone andproduce many jet-black seeds. Roots are woody andbranched.

HOW DOES IT EFFECT THE ENVIRONMENT?Buckthorn is invasive in disturbed areas, however itdoes not require disturbance to become established. Ithas a fast growth rate, rapidly forming dense thicketsthat shade out native plant species and alter the

vegetation structure. It competes aggressively, beinglarger and faster growing than native shrub species.Buckthorn reduces native species diversity throughhabitat degradation and altering the natural communitycomposition. This then significantly alters habitatstructure and food sources for native fauna, creating anenvironment more suited to introduced flora and fauna.

HOW DOES IT SPREAD?Readily regenerates by seed. Dispersal is assisted bybirds and mammals that eat the fleshy berries.Buckthorn often emerges under trees and shrubs whereseeds have been dropped by birds.

HABITATBuckthorn prefers a climate with dry summers andintermittent rain during winter. Buckthorn can grow inshady conditions and is commonly found in coastalshrublands.

WHERE IS IT FROM?Mediterranean region and was introduced to Australia asan ornamental garden hedge.

DISTRIBUTIONIn South Australia it is found in temperate areas near thecoast from Eyre Peninsula to the South East. Buckthornalso occurs throughout the Yorke Peninsula, NorthernLofty, Southern Lofty, Murray and South East in SouthAustralia. It is also found in New South Wales andVictoria.

DON’T CONFUSE IT WITH…Buckthorn is similar in appearance to Sea box (Alyxiabuxifolia). Sea box has leaves that are less than 4cmlong, paired and rounded at the tips. Flowers are whiteand waxy.

Victor HarborVictor Harbor

SUCCULENTSThese pages show a range of succulents that arerapidly invading our coastline. The term succulent isbroadly used to define a group of plants with thick,fleshy leaves or stems that can store water. They areusually found in tropical and subtropical dry regions,but have been introduced into the coastal environment.

Succulents have a negative effect on our coastalbushland. Succulents increase the amount of nutrientsin the local environment. This leads to the subsequentinvasion by other weeds that would not normally be

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GrangeAgave americana

Billy Goat FlatAeonium sp. TennysonCotyledon sp.

GrangeAptenia cordifolia

able to grow in these low nutrient environments. Duneformation is also altered, and the visual amenity of anarea is significantly decreased.

Succulents reproduce vegetatively when segments ofstems break off and take root to form a new plant.Segment can take root up to several months afterbreaking off from the parent plant, even when not onsoil or sand. For this reason, it is important to removeall material from the environment, and never dumpweeds in inappropriate places such as bushland orroadsides. Instead, put them into compost to benefityour garden.

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GrangeKniphofia sp.

REFERENCES

Dashorst, G. & Jessop, J.P. Plants of the Adelaide Plains& Hills, Finsbury Press, Adelaide, 1998.

Handbook for Revegetation and Weed Control in theSouthern Fleurieu Dunes by Ron Taylor for South CoastDune Care, 2000.

NSW Department of Land and Water Conservation 2001,Coastal Dune Management: A Manual of Coastal DuneManagement and Rehabilitation Techniques, CoastalUnit, DLWC, Newcastle.

Oppermann, A. A Biological Survey of the SouthAustralian Coastal Dune and Clifftop Vegetation,Department for Environment, Heritage and AboriginalAffairs 1999.

Prescott, A. It’s Blue with Five Petals, OpenbookPublishers, South Australia, 1994.

Robertson, M. Stop Bushland Weeds: A guide tosuccessful weeding in South Australia’s bushland, TheNature Conservation Society of South Australia Inc,1997.

For further information, contact:The Coast and Marine Branch, Natural and Cultural Heritage, Department for Environment and Heritage.Ph: 8124 4877 Fax: 8124 4920 or visit our website; www.coasts.sa.gov.au

Coastline Project Officer:Amy-Jane BruckmanSA Urban Forest Biodiversity Program

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COAST PROTECTION BOARD