Beneath the tnulga of ths hower inland. at'eas of Western Australia tbere can be'seenone of the State\ tnost sI)ectacubrr sights.A cntpet of ewrlastings - yellow,pinh and. white - sparhlesin the san for asfar as the ele ca,nse,. by SuzanneCurry aisies belong to the familY to 20 centimetresin height,with tiny mechanismfor breakingdormancy. That germinate Asteraceae, also knor,ln as yellow compoundflower-heads that are is,theseedswill probablyonly Compositae.They have an almostworld- lessthan four millimetres in diameter.It when sufficientextemal moisture is growth. widedistribution; theAntarctic mainland is widespreadthroughout the southern availablefor continuing genus 'slime' is the onlyplace that theydo not grow. parts of WesternAustralia, where it Another containing The Asteraceaeis one of the largest commonlyoccurs on the edgeof saline cells on the fruil is Bletmospora,an genus familiesofflowering plants in theworld, depressionswith saltbush,though it may Australian of two species, andis representedby morethan I 100 alsooccur in openshrubland. includingB. drummondii.This species generaand as manyas 25 000species. A particularly interesting is an annualherb up to 10 centimetres as in other parts of the characteristicof Pogonolepisand some high.The leaves are often more or less In Australia, 'slime' world, manyspecies occur in arid and otherclosely related genera is the succulent,are held erect, and the grow semi-aridareas. In a singleregion, one cells of the fruit, which createa sticlg uppermost leavesusually above part or a few speciesoften dominate and mucuswhen wet. The function of these the flowers. The flowering of the cover vast areas.The successof the cellsis debatable- it hasbeen suggested plantcomprises about l0 to25 composite familystems mainly from theadaptability that the stickynature is importantin flower-heads,known as capitula. Each ofthe species and their hi gh reproductive fasteningthe fruit (achene)to the soil capitulumis a clusterofsmall individual rate, accounting for both its particles during germination.Another flowers or florcIs. Blennosqora grantsin cosmopolitannature and the factthat its possibilityis that the cells and their drummondii anarray ofhabitats speciesfrequently becomewidelY degreeof water uptakeand./or period of in the south-westof WesternAustrali4 distributedweeds. In WestemAustralia hydration are associatedwith some the southern part of South Australia, there are about 500 speciesand 140 generaof Asteraceae. Daisiescover such a widearea and occur in so many habitatsthat it is not surprisingto find numerousgrowth forms.The biggest daisy in theworld is a tree!Native to the GalapagosIslands about2 000 kilometreswest of South Americain the PacificOcean, Scalesla pedunculata carrgrow to more than 20 metres high and forms the mountain cloud forests of the islands' Wth few competitivetree-species onthese oceanic islands,Sca/esza may have evolved to fill a vacantniche, In starkcontrast, Australia's daisies arecommonly annual or perennialherbs, Pogonolepkstricta is onesuch example. This small annualherb is commonlyup I Preoiouspage I Marrl' Thewhite flowersPider is I perfectlycamouflaged on thewhite e\mlastingWaitzia sauaeoleta. Photo- Jid lrchman t6et' A carpet of everlastings. Photo- Raycranfield Aboue right: Bletmospora dtummondii I 'slime' I is a sDeciesthat contains cellson I the fruit. Photo- B..A"Fuhrer I Rrgrt' The climbing daisy | (Brachgscomelatisquameal is the I largest of the genus. Photo- Jiri lrchman 42 uuoscora andin partsofwestern Victoria. floretsthat are up to thyee Not all our daisiesare small herbs. centimetreslong. For example,the climbing daisy Thenorthern areas of (Brac hg sc o me la t is quamea) cznb e f ound, the Stateare not without onthe sand of the north-west coast. Thrs their fair share of is the largestspecies of the genus,and Asteraceae,though the scramblesover other shrubs to a height grasslandshide manyof of two metres.The flower heads, which the smaller annuals. arethree to four centimetresacross, are Olearia arguto is an usuallypink. TheBra c h g s come (f ormerly attractive shrub that Brachgcomel genus provides many growsin a varietyof soils beautifulexamples of daisies.Of about throughout the 90species, I8 occurin WesternAustralia. Kimberley.The large The pretty Swan River daisy leavesare often covered (Brachyscomeiberidifolia) is an erect, with densewhite hairs, branchingannual that cangrow to 45 givingthem a soft,grey- centimetrestall, but is often shorter. greenappearance. The Thewhite or violetouter, petal-like ray solitary headsextend on florets are up to one-and-a-half long stalks abovethe centimetreslong. leavesand have white, The jarrah forest providesmany blueor purpleray florets lovelyexamples ofdaisies, including the to about one-and-a-half familiar native gerbera(Trichocline centimetreslong. spathulata), amember ofagenus mostly The ephemeral (short-lived) drummondiiand also pink everlastings nativeto SouthAmerica.It is acommon everlastingsof the mulgaand spinifex (Schomiacassiniana\. forestdweller, from Ginginto Augusta, scrub provide some of the most Suchspectacular sights point to the with singleflower heads of creamyray spectaculardisplays created by the importanceof the Asteraceae,Names daisies.In thesedry areasrain falls such as asler.calendula, zinnia, irregularlythroughout tle year,and after chrysanthemumand gerbera are only a heavywinter rains the redsoil iscarpeted fewthat arefamiliar to boththe home with theseephemerals. The splendid gardener and the commercial everlasting(Rhodanthe chlorocephala horticulturalist.The wildfl ower tourism subsp.spleadtda, previously known as industrymarkets many tours based lAboae right: The native gerbera on | (Trichocline spathulala) growing in Helipterum splendidum) has solitary the displaysof the everlastings.Daisies I John ForrestNational Park, near Perth. creamor white flower-headsup to six arealso an importantcomponent ofthe - Photo P.Armstrong centimetresacross and is the largestof dried-flower export industry. Belora;A solitaryburrowing bee on the ephemeraleverlastings. GrowinE I yellow POLLINATIONADAPTATIONS I variablegroundsel (Seaecio lautusl. amongthese can be foundthe I Photo- Jiri lnchman pom-pomeverlastin Es of Cepholipterum In the daisies,nectar is secretedat the baseof the narrowpetal-tube. As it accumulatesit fisesto thewider part of the tube,where it is protectedftom the rain by the anthers.The nectar is easily accessibleto all insects,and notonlythe short-tonguedinsects. Among the many inseclpollinators are moths, butterflies, true flies and ants, but the marn pollinatorsseem to be the bees.Some beesare known to sleepin the daisy flower.This is the casewith the male solitaryburrowing bee, which can often be foundin everlastingflowers. Unlike insects,which collect nectar or pollen, thewhite flower spider uses the daisy in a differentway. This spider is common, althoughdifficult to detect,on thewhite everlastings;its perfect camouflage allowsit to waitin preyfor unsuspecting insectsto visit the flowerhead. unoscope43 ECONOMICUSES sunflower (Helianthussp.) and the hasmany accidentally introduced daisies lndirectly,the familyAsteraceae plays safflower(Carthamus sp.) are twospecies thathave become unwanted crop weeds, an importanteconomic role in many introducedto WesternAustralia and such as the slenderthistles (Carduus partsofthe world. It suppliesfood plants, cultivatedfor their seedoil. sp.),skeleton weed (Chondrilla juncea) , sourcesof raw material,medicinal and On the debit side,the Asteraceae boneseed (Chrgsanthemoides drugplants,and plants forthe cut-flower family includesweeds and poisonous monilifera) and Noogooraburr and tourism trades.For example,the plants.Unfortunately, Western Australia (Xonth i umoccident a/e). But not all crop weedshave been accidentally introduced. Capeweed,one of the State'smost widespreadand commonly known daisy weeds,was originally introduced from SouthAfrica as a pastureplant. Herbs(or plantsuseful to humans) havealways been popular, and the daisy familyprovides many examples. Most of our wild herbshave been introduced from overseasand have become weeds. Yarrow(Achillea millefolium) is awell- known,introduced plant, its fameas a wound-healingherb attractingmuch scientificstudy. Many herb spectes containessential oils or, like tarragon (A.rtemisiadracunculus\, are used for culinarypurposes.Others, such as absinthe (Artemisia absinthiuml, are usedin medicine. Yetanother introduced plant of the daisyfamily is thedandelion (Taroxacum oflicinalel.Dandelion has an amazing rangeofuses - assalad plant, vegetable, coffeesubstitute, wine and beer ingredient,and medicine. The leaves are still widelyused in Europeas a salad herb and vegetable.The dandelion's scientificname indicates its medicinal properties- Tararacum meaning 'remedyfor disorders'and officinale implyingmedical use. Dandelion is still usedin many herbaltonics. Western Australiahas its ownequivalent, a plant commonlyknown as native dandelionor .1 . lAboae left: The compoundflower lheads ol Actinobole oldfieldiqna ate I onlyabout a centimetrein diameter. Photo- RayCranfield I left The yeflow-floweredOlhonna lgregorii and while ev€rlasting | (Rhodanfhefloibunda) grow together in the Goldfieldsof WA. Photo- M.& I. Morcombe 44 ^*"ro"u native yam (Microseris scopigera). Superficiallyresembling the introduced dandelion,it wasused as a foodsource by the Aborigines,who roastedthe fleshy roots. THEWORK OF THE HERBARIUM The WesternAustralian Herbarium, which is part of the Departmentof Conservationand
Details
-
File Typepdf
-
Upload Time-
-
Content LanguagesEnglish
-
Upload UserAnonymous/Not logged-in
-
File Pages6 Page
-
File Size-