Table Of ContentNuytsia 11(3):353-364(1997) 353
Ataxonomic reviewofStylidium subgenusForsteropsis(Stylidiaceae)
AllenLowrie1andKevinF.Kenneally2
'6 Glenn Place, Duncraig, 6023
Science Publications Unit, Corporate Relations Division, Department of Conservation and Land Management,
Locked Bag 29, Bentley Delivery Centre, Western Australia 6983
Abstract
Lowrie, A. and Kenneally, K.F. A taxonomic review of Stylidium subgenus Forsteropsis
(Stylidiaceae).Nuytsia11(3):353-364(1997). ThreenewspeciesofStylidiumWiM.(Stylidiaceae)from
south-westWesternAustralia,Stylidiumleeuwinense,S. marradongenseandS. semaphorumLowrie
&
Kenneallyaredescribedandillustrated. DescriptionsandillustrationsofS. imbricatumBenth. and
S. preissii (Sond.) F. Muell. are provided for comparison and to complete this review ofStylidium
subgenusForsteropsis (Sond.) Mildbr.
Introduction
ThispaperpresentsataxonomicreviewofStylidiumsubgenusForsteropsis(Stylidiaceae)which
comprises five species of triggerplant from south-western Australia including three new species
describedhere. AllmembersofthissubgenusofStylidiumWilld.arecharacterizedbybeingplantswith
tightlyappressed leavesspirallyarrangedaroundthestems. They arereferredtounderthecommon
namesLizardTriggerplantforS.pre/ssnandTile-leavedTriggerplantforS.imbricatum(Erickson1958)
aswell asforthethreenew species.
Taxonomy
StylidiumsubgenusForsteropsis(Sond.)Mildbr.(Mildbraed1908:31,33). -ForsteropsisSond.(Sonder
1845: 393). Type: ForsteropsispreissiiSond. [=Stylidiumpreissii(Sond.)F.Muell.]
Stylidiumser. ImbricataeBenth. (Bentham 1869: 21). Type:StylidiumimbricatumBenth.
KeytospeciesofsubgenusForsteropsis
1 Flowersinumbellateracemes. Stigmaround,cushion-shaped S. preissii
1: Flowersinspike-likeracemes. Stigmaconical,capitate 2
2 Hypanthium glabrous
3
2: Hypanthiumglandular 4
: 1
354 Nuytsia Vol. 11, No. 3 (1997)
3 Leaveswithalongapicalpoint. Sepalsobovate S.imbricatum
3: Leaves lackingan apicalpoint. Sepalsovate S.leeuwinense
4 Sepalsovate, apexacute. Corollalackingthroatappendages S.marradongense
4: Sepalsnarrowlyovatewithapicalmucro. Corollawiththroatappendages S.semaphorum
Stylidium imbricatum Benth.(Bentham 1837: 73). Type: InteriorofKingGeorgeSound, [Western
Australia],Huegel(holo K;iso:fragmentattachedtoHarvey,KingGeorgeSound,MEL710000).
Perennialherb,witherectdividedstemscoveredwithappressed,tile-likeleavesspirallyarranged
mm mm
aroundthestem. Leavesbasifixed,green,ovate-elliptic,1.5-1.8 long,0.6-0.8 wide,withsilvery
whitemucro0.6-0.8mmlong,piloseatthebase,hyalinemarginssilverywhite,dentate-laciniate.Racemes
mm mm
terminal,spike-like;pedicels1.5-2 long;bractssilverywhite,c.3 long,fringed;bracteolessimilar,
c. 2mmlong. Hypanthiumobovoidatanthesis,c.2.5mmlong,c. 1 mmwide,glabrous. Sepalsfreeto
base,obovate, c. 2mm long,glabrous;hyalinemarginsilverywhite,fringed. Corollareddishviolet,
mm mm mm
withlaterally-pairedlobes;anteriorlobesc.4.5 long,c.3 wide;posteriorlobesc.4.5 long,
c.3mmwide. Labellumsubulate,reddishandblackatthebase,c.2.9mmlong,c.0.7mmwide,mmmargins
bearing longhair-likestalkedglands,with2basalacicularappendages;appendages c. 1.5 long,
reddish maroon, themarginsbearingafew longhair-like stalkedglands; boss ovate, white, smooth,
c. 0.7mm long,c. 0.5 mm wide. Throatappendages8,the2nearthelabellumc. 0.5 mm,thenext2
c. 1mmandthe4remainingonesc.0.7mmlong.Gynostemiumcolumnc.8mmlong;anthersblack,pollen
paleyellow;stigmaconical,capitate.(Figure 1)
Selectedspecimensexamined.WESTERNAUSTRALIA:PorongurupRange,Apr. 1939, W.E.Blackall
(PERTH); BabyBarnettHill,34°24’S,117°51’E,20Apr. 1980,R.J.Cranfield1425(PERTH);Stirling
Range,NofAlbany,May, R. Ericksons.n. (PERTH);BaseofMtToolbrunup,StirlingRange,23Apr.
1923,C.A.Gardners.n.(PERTH);AboveMondurup,StirlingRange,4May1964,C.A.Gardner1471
(PERTH); FootofNsideofBluffKnoll,StirlingRange,1June1958,A.S.Georges.n.(PERTH);2miles
[3.2km]WofKarribankonPorongurupsroad,280ct. 1966,S.H.Jamess.n.(PERTH);2kmSEofEllen
Peak,StirlingRange,11May1982,G.J.Keigheiy4949(PERTH);MondorupPeak,0.5kmupfromroad,
SOtnirSlionugtRhaCnogaes,t3H4i°g2h4w’aSy,1147.°74k9m”EN,E19ofApCrh.ey1n99e4s,BKe.aF.chKetunrnne-aolffl,yE1 o1f44M3an(yBpRe1a,kCsB,,2DMNaAy,M19E9L1,,APELRoTwHr)i;e
583(PERTH);CheyneBeach,20Apr. 1960,G.Starkies.n.(PERTH);6.9miles[11km]NNEofCheynes
Beachturn-offonHighway1,22Mar.1970,M.D. Tindale315&B.R.Maslin(K);ChesterPass,Stirling
Range,4Sep. 1947,J.H. Willis12(PERTH).
Distribution. StirlingRangeNational Park, PorongurupRangeandsouth-easttoCheynes Beach.
Habitat. Growsinlateritesoilsoftenmixedwithalittlewhitesand.
Floweringperiod. April-May.
Conservationstatus. Notconsideredtobe atrisk.
Affinities. StylidiumimbricatumisdistinguishedfromallothermembersofsubgenusForsteropsisby
having obovate sepals.
A. Lowrie & K.F. Kenneally, A taxonomic review ofStylidium subgenus Forsteropsis 355
Figure 1 Stylidium imbricalum A - habit of flowering plant; B - section of stem showing spirally arranged leaves;
C - leaf, enlarged section left; D - hypanthium; E -sepal; F - corolla; G - labellum; H-throat appendages; I - lateral
view ofgynostemiumtip (with conical, capitate stigmaatright); J - frontview ofgynostemium tip (with stigmagrown
out, right); K. - back ofgynostemium tip. Scale bar for all = 1 mm. Drawn fromA. Lowrie 583.
:
356 Nuytsia Vol. 11, No. 3 (1997)
StylidiumleeuwinenseLowrie&Kenneally,.?/).nov.
S. imbricatoBenth.affinissedsepalissubulatis,foliisacumeneapicaliabsentiatquefoliisquatuor
circumcaulem dispositisdiffert.
Typus: SouthcomeroftheintersectionofScottRiverRdandGovenorBroomeRd,c. 0.5km northof
BrennansFordontheScottRiver,WesternAustralia,34°17’S,115°25’E,26May1996,A.Lowrie1465
(,holo PERTH04431170;iso:MEL).
Perennialherb,witherectdividedstemscoveredwithappressed,tile-likeleavesspirallyarranged
aroundthestem. Leavesbasifixed,green,lanceolate,2.5-3.5mmlong,0.5-0.8mmwide,acute,without
anapicalmucro,piloseatthebase,hyalinemarginssilvery'white,dentate-laciniate. Racemesterminal,
mm
spike-like, flowers almost sessile; bracts silvery white, c. 3 long, fringed; bracteoles similar,
c. 2.5mmlong. Hypanthiumobovoidatanthesis,c.2.5mmlong,c. 1 mmwide, glabrous. Sepalsfree
mm
tobase,ovate,c. 1.5 long,glabrous;hyalinemarginsilverywhite,serrate, surroundingasubulate
body. Corollareddishpurple,withlaterally-pairedlobes;anteriorlobesc.4 mmlong,c. 2.2mmwide;
posteriorlobesc.3mmlong,c. 1 8mmwide. Labellumlanceolate,maroon,c.3mmlong,c.0.5mmwide,
margins bearing long white hair-like stalked reddish glands, with 2 basal acicular appendages;
mm
appendages c. 1.5 long,themarginsbearingafewlonghair-likestalkedglands;bossovate,white,
smooth, c. 0.5 mm long, c. 0.3 mm wide. Throat appendages 8, the longestones c. 1.5 mm long.
mm
Gynostemium column c. 1 long; anthers maroon, pollen pale yellow; stigma conical, capitate.
(Figure2)
Otherspecimens examined. WESTERN AUSTRALIA: Nut Rd and FicifoliaRdjunction, Walpole-
NornalupNational Park, 3 Oct. 1988,A.R. Annels261 (PERTH); Walpole-NornalupNational Park,
35°14’00”S, 6°52’30”E,3 Mayl989,/U?..4«/7e/ss'.«.(PERTH);200mSofMilyeannupCoastRoad,
1 1 1
1.7kmNEofintersectionwithRobertsRd,4Apr. 1991,N.GibsonScM.Lyons]1 18(PERTH); ScottRiver
sandplain, 18Apr. 1976,S.D. Hopper2294(PERTH); Chesterblock,AugustatoNannup,34° 1 1’ S,
1 15°20’E,26May 1992,G.J. Keighery13451 (PERTH); Quarram,23miles[36.8km]WofDenmark,
31July1953,/?.Melville4461 &R.D./?oyce(K,MEL,NSW,PERTH);NearMtLindsay,1879,Muirs.n.
(MEL,PERTH);BetweenBowandDenmarkRivers,20Apr.1960,G.Starkies.n.(PERTH);ShannonRiver,
9Apr. 1979,Surveyteam1555(PERTH).
Distribution. Coastal regionsbetween Augustaand Denmark.
Habitat. Occurs in blacksandysoilon swampyheathland.
Floweringperiod. February-May.
CALM
Conservationstatus. ConservationCodesforWesternAustralianFlora:PriorityThree. Although
extendingoverawidedistribution,Stylidiumleeuwinense isknownfromrelativelyfewlocationswith
smallpopulations. Thetypelocation issituatednearanactivemininglease. Thispopulationcouldbe
threatenedwith extinction ifsandminingandassociated activitieswere undertaken atthe sitebefore
amanagementplan forthespecies was inplace.
Etymology.Theepithet,leeuwinensereferstotheCapeLeeuwinregioninsouth-westWesternAustralia
which isthetype location forthis species.
A. Lowrie & K.F. Kenneally, A taxonomic review ofStylidium subgenus Forsteropsis 357
Figure 2. Stylidium leeuwinense A - habit offlowering plant; B - section ofstem showing spirally arranged leaves;
C - leaf, enlarged section left; D - hypanthium; L -sepal; F - corolla; G -labellum; H - throat appendages; 1 - lateral
view ofgynostemium tip (with conical, capitate stigma atright); J - frontview ofgynostemium tip (with stigmagrown
out, right); K.- back ofgynostemium tip. Scale bar for all = 1 mm. Drawn from A. Lowrie 1465.
358 Nuytsia Vol. 11, No. 3 (1997)
Affinities.StylidiumleeuwinenseisdistinguishedfromS.preissiibyitsspike-likeracemesandfromall
otherspecies in subgenusForsteropsisbyhaving leaveswithout an apicalmucro.
StylidiummarradongenseLowrie&Kenneally,.?/?.nov.
S. imbricatoBenth. affinis sedsepalis ovatis, corollaappendicibus faucisabsentibus differt.
southendofTunnelRd,Marradong,WesternAustralia,32°55’S, 116°28’E, 14 Octoberl993,
A.Lowrie807(holo:PERTH04431189;iso:MEL).
Perennialherb,witherectdividedstemscoveredwithappressed,tile-likeleavesspirallyarranged
mm mm
aroundthestem.Leave.?basifixed,green,lanceolate, 1.5-2 long,0.5-0.8 wide,withapicalsilvery
mm
whitemucro0.7-1.5 long,piloseatthebase,hyalinemarginssilverywhite,dentate-laciniate. Racemes
mm mm
terminal,spike-like;pedicels 1-1.5 long;bractssilverywhite,c. 3.5 long,fringed;bracteoles
mm m mm
similar,c.2.5 long.//ypa«rL;wOTObovoidatanthesis,c.3.5 long,c. 1.5 wide,glandular.Sepals
mm
freetobase,ovate,c.2 long,acute,upperhalfglabrous,lowerhalfglandular;hyalinemarginsilvery
white, fringed. Corolla white or various shades ofpink, with laterally-paired lobes; anterior lobes
mm mm mm mm
c. 5 long, c. 3 wide; posteriorlobesc. 5 long,c. 2.5 wide. Labellum ovate, white,
mm mm
c. 1.5 long,c.0.6 wide,marginsbearinglonghair-likestalkedglands,with2basalsubulate
mm mm
appendages;appendagesc.0.6 long,glabrous;bossnarrowlyovate,white,smooth,c.0.7 long,
c. 0.3 mm wide. Throat yellow, bordered by prominent reddish markings, without appendages.
mm
Gynostemiumcolumnc. 7.5 long;anthersmaroon,pollengreyishwhite;stigmaconical,capitate.
(Figure3)
Otherspecimens examined. WESTERN AUSTRALIA: Tunnel Rd, Worsley mine site, 10 km S of
Boddington, 26 Sep. 1982, K.J. Atkins KA210 (PERTH); Junction ofFletcher Rd and Tunnel Rd,
BGoudldliynngetaorn,M3t2S°a3d7’dlSe,b1a1c6k°,29M’aEr,ra14doOcntg.,119393No.Kv..F.1K9e0n4n,eAallMyor1r1i3s9o6n(B1R4I1,8C1A(NKB,,PEKR,TMHE)L.,NSW,PERTH);
Distribution. Occurs fromMtSaddlebacktoMarradong.
Habitat. InlateritesoilsinopenJarrahforest(Eucalyptusmarginata)withBanksiagrandis,Dryandra
sessilis and Persoonia longifolia.
Floweringperiod. October.
Conservationstatus.CALMConservationCodesforWesternAustralianFlora:PriorityOne. Stylidium
marradongense isonlyknownfromafewlocations. Thesmallpopulationatthetypelocation, which
issituatedwithinanactivebauxitemininglease,couldbethreatenedwithextinctionifminingandrelated
activitieswerecommencedbeforeamanagementplanforthespecies wasinplace.
Etymology. The epithet, marradongense refers to the Marradong region in south-west Western
Australiawhere this species occurs.
Affinities. StylidiummarradongenseandS.preissiiboth lackthroatappendages. S. marradongense
isdistinguishedfromS.preissiibyhavingleaveswithanapicalmucro,terminalspike-likeracemesand
conical,capitatestigmas.
A. Lowrie & K.F. Kenneally, A taxonomic review ofStylidium subgenus Forsteropsis 359
Figure 3. Stylidium marradongense A - habitofflowering plant; B - section ofstem showing spirally arranged leaves;
C - leaf, enlargedsection left; D- hypanlhium; E - sepal; F - corolla; G - labellum; H - lateral view ofgynostemium tip
(with conical, capitate stigma at right); 1 - front view ofgynostemium tip (with stigma grown out, right); J - back of
gynostemium tip. Scale bar for all = 1 mm. Drawn from A. Lowrie 807.
360 Nuytsia Vol. 11, No. 3 (1997)
Stylidiumpreissii(Sond.)F.Muell.(Mueller1863:122).-ForsteropsispreissiiSond.(Sonder1845:383).
Type:CapeRiche,[WesternAustralia],22November1840,L.Preiss438(holo:MEL709983;iso:LD,
MEL).
Perennialherb,withshorterectbranchingstemscoveredwith appressed,tile-like leavesspirally
mm mm
arrangedaroundthestem.Leavesbasifixed,green,broadlytrullate,e. 1.9 long,c. 1 wide,acute,
withsilverywhitehyalinemargins,fringedatbaseandciliateabove. Racemesumbellate;flowersalmost
mm
sessile;bractsandbracteolessimilar,silverywhite,c. 2.4 long. Hypanthiumobovoidatanthesis,
c. 2.5 mm long,c. 1.2mm wide,glabrous. Sepals2joinedalmosttotheapex, 3 freetobase, ovate,
c. 3 mm long, glabrous;hyalinemarginsilverywhite,serrate,surroundingasubulatebody. Corolla
6mm mm
white,paleordarkpink,withlaterally-pairedlobes;anteriorlobesc. long,c.5 wide;posterior
lobesc.6mmlong,c.3.5mmwide. Labellumovate,white,c.2.5mmlong,c.2.2mmwide,marginsdentate,
mm mm
eachtoothbearingalongstalkedgland;bossnarrowlyovate,white,smooth,c.0.9 long,c.0.25
wide. Throatwithoutappendages. Gynostemium columnstrap-like,hingedbelowtheanthers,with
adilatedcunabulum where the anthers or stigmarest inthe setposition abovethe sensitive torosus,
c. 5mmlong;antherslilac,pollenwhite;stigmaround,cushion-shaped.(Figure4)
Selectedspecimensexamined.WESTERNAUSTRALIA:BranchCircusandHammondRds,Jandakot,
9Nov. 1965,J.C.Anway542(MEL,NSW,PERTH);CapeLeGrande,5Nov. 1967,Carlquist4013(M,
NSW,PERTH),4031(NSW);BeenyupRd.c. 1mile[1.6km]SofJandakotSiding,270ct.1963,A.S.George
5295:NEofJerramungup,30Oct. 1965,A.S.George7024(PERTH);29.3kmNEofManypeaks,9Dec.
1986,/I.Lowries.n.(PERUl);Tum-offtoHellfireBay,CapeLeGrandNationalPark,8Dec.\990,A.Lowrie
s.n.(PERTH); OnthecomerofStockyardRdandMerivaleRd,EofEsperance,28Nov. \993,A.Lowrie
844(PERTH);AtthejunctionofHellfireBayRdandLuckyBayRd,CapeLeGrandNationalPark,Eof
Esperance,28Nov. 1993,A.Lowrie847(PERTH); OnCapeLeGrandRd,2.4kmSofMerivaleRd,Eof
Esperance,29Nov. 1993,A.Lowrie851(PERTH);FromtheFitzgeraldRangetoCapeLeGrande, 1867,
Maxwells,n.(K);NsideofWoogenellupNorthRdfromthejunctionwithChesterPassRd,13Dec. 1992,
F.H. &M.P. Mollemans4393(PERTH);BalladoniaRd,SofMtRaggedonwesternboundaryofCape
W
AridNationalPark,29Nov.1971,R.D.Rovce9905(PERTH);c.50km ofIsraeliteBay,E. WittwerW\900,
17Nov.1976(PERTH).
Distribution. BremerBaytoIsraeliteBaywithdisjunctpopulationsatJandakot.
Habitat. Grows inwhitesilicasand inopenheathland.
Floweringperiod.November-December.
Conservationstatus. Notconsideredtobeatriskatlocationsalongthesouthcoastalregion. However,
thedisjunct Jandakotpopulations(J.C. Anway542andA.S. George5295)arepresumedtobeextinct
owingtourbandevelopment.Thereisanurgentneedoffurthersurveytoestablishifotherpopulations
existwithinthePerthregion.
Affinities. Stylidiumpreissii is distinguished from all other members ofsubgenus Forsteropsis by
havingastrap-likegynostemiumcolumn,hingedbelowtheanthers,withadilatedcunabulumwherethe
anthers or cushion-shaped stigmarest in the set position above the sensitive torosus.
A. Lowrie & K.F. Kenneally, A taxonomic review ofStylidium subgenus Forsteropsis 361
Figure 4. Stylidiumpreissii A - habit offlowering plant; B - leaf, enlarged section left; C - hypanthium; D - corolla-
E - labellum; F - lateral viewofgynostemium tip (with cushion-like stigmaatright); G- adaxial viewofgynostemium'
anthers atthe apexwith clavate moniliform hairsalongthemargins, showinghinged portion (dotted) immediately below
the anthers and the dilated cunabulumthatthe anthers fold upon when the gynostemium is in thesetposition' H - front
vDireawwnoffrgomynAo.stLeomwriiuems.tni.p9wiDtehc.st1i9g86m.a grown out; I - back of gynostemium tip. Scale bar for all ’= 1 mm
362 Nuytsia Vol. 11, No. 3 (1997)
Stylidiumsemaphorum Lowrie&Kenneally,sp.nov.
S. imbricatoBenth. affinissedsepalisangusteovatisetapicalitermucronatisdiffert.
Typus:GreatNorthemHighway[preciselocalitywithheld],WesternAustralia,4October1993,A.Lowrie
804(holo:PERTH04431197;iso:MEL).
Perennialherb,witherectdividedstemscoveredwithappressed,tile-likeleavesspirallyarranged
mm mm
aroundthestem. Leavesbasifixed,green,narrowlyovate,2-2.3 long,0.5-0.7 wide,withsilvery
whiteapicalmucro 1.2-2mmlong,piloseatthebase,hyalinemarginssilverywhite,dentate-laciniate.
mm mm
Racemestermma\,spike-like;pedicels1.5-2.5 long;bractssilverywhite,fringed,c.2.5 long,with
c. 1.5mmlongmucro;bracteolessimilar,c.2mmlong,withc.0.7mmlongmucro. Hypanthiumobovoid
mm mm mm
atanthesis,c.2.5 long,c. 1 wide,glandular.Sepalsfreetobase,narrowlyovate,c.2.5 long,
mostlyglabrousexceptforthebase;hyalinemarginsilverywhite,fringed,withashortbrownishapical
mucro. Corollapalepink,rarelywhite,withlaterally-pairedlobes,buttheseappearingverticallypaired
inrelationtotheplant,with the lowerlobes(acombination ofan anteriorandposteriorlobe)placed
togethertoprovideaninsectpollinator’slandingplatform,theupperlobesspreadapartinasemaphore-
mm mm mm mm
likearrangement;anteriorlobesc.5 long,c.2.3 wide;posteriorlobesc.5 long,c.2.3 wide.
mm mm
Labellumsubulate,reddish,c.2.5 long,c.0.5 wide,marginsbearinglonghair-likestalkedglands,
mm
with2basalsubulateappendages;appendages c. 0.8 long,papillose;bossnarrowlyovate,white,
smooth,c.0.9mmlong,c.0.3mmwide. Throatappendages6,the2nearthelabellumpinkandc.0.7mm
long,theremaining4whiteandc.0.4mmlong, followedby4darkpinkthroatmarkings. Gynostemium
columnc. 5mmlong;anthersdarkbrown,pollenwhite;stigmaconical,capitate.(Figure5)
Other specimens examined. WESTERN AUSTRALIA: Great Northern Highway, 21 Oct. 1966,
AR..ELroiwcrkiseon3s3.3n.(P(EPERRTTHH)),;1G1rOecta.tN1o9r96t,hAemLHoiwgrhiwea1y3,5351(APuEgR.T1H9)9.1,A.Lovw7e298(PERTH),28Sep.1991,
Distribution. Knownonlyfromthetype location.
CALM
Habitat. GrowsinlateritegravelsoilswithDryandrasessilis, onahillsummit,withina Nature
Reserve.
Floweringperiod. September-October.
Conservationstatus.CALMConservationCodesforWesternAustralianFlora:PriorityTwo.Stylidium
semaphorumisknownfromonlyonesmallpopulationwithinanaturereserve.
Etymology. ThespecificepithetsemaphorumisfromtheGreeksema-signandphoros-bearingand
alludestothesignallingmethod ofsendingmessagesbysemaphore, wherebyapersonholdingaflag
in each hand anglestheflagsto codepositionsto relayvisual messages. Theuppercorolla lobes of
Stylidium semaphorum are displayed like a flag-like semaphore signalling its position to attract
pollinatorsfromtheirflightpaths. Itisinterestingtonotethattheupperlobesofthecorollaarepositioned
inaV-shapewhichisthesemaphorecodefor“U”and“attention”.
Affinities.StylidiumsemaphorumisdistinguishedfromallothermembersofsubgenusForsteropsisby
havingsepalswithashortbrownish apicalmucro.
