Stylidium pulviniforme (Stylidiaceae), a new species of triggerplant from south-west Western Australia

5 Pages·1994·1.2 MB·English

by  Allen Lowrie

Nuytsia9(3): 369-373(1994) 369
Stylidiumpulviniforme (Stylidiaceae), a newspecies oftriggerplant from
south-westWesternAustralia
AllenLowrie'andKevinF. Kenneally^
'6GlennPlace,Duncraig,WesternAustralia6023
WesternAustralianHerbarium, DepartmentofConservationandLandManagement,
POBox 104,Como,WesternAustralia6152
Abstract
Lowrie, Allen and Kenneally, Kevin F. Stylidiumpulviniforme (Stylidiaceae), a new species of
triggerplant from south-westWestern Australia. Nuytsia9 (3); 369-373 (1994). A new species of
Stylidium (Stylidiaceae) endemic to south-west Western Australia, S. pulviniforme Lowrie and
Kenneally, isdescribedandillustrated.
Introduction
Stylidiumpulviniforme describedin thispaperisendemic tothesouth-westofthe state where it
appears tobeconfinedto whitesandon themarginsofwinterfreshwaterpools andinsalt-free soils
abovethehighwaterlineofsaltlakes. ItbelongstosubgenusNitrangiumEndl.,sectionSonderella
Mildbr. (Mildbraed 1908)andismost closelyrelatedtoS. corymbosumR.Br.andS. lepidumBenth.
Taxonomy
StylidiumpulviniformeLowrieandKenneally, sp. nov. (Figures 1 and2)
Herbaperennisparvula,caudicecaespitoso,ramosopulviniformi. Foliaomniaradicalia, lineari-
lanceolata, marginehyalino, adapicem serrata, infracarinata, mucronata, 3mm longa,0.9 mm lata,
glabra. Inflorescentiadenseglandulosa,2.5-4.5cm alta. Flores 3-5 incymaparva. Inflorescentiae
mm mm
bracteaelineares,1-2 longae;bracteolae0.6 longae. Calycistubusglanduloso-pubescens,4.5
mm mm
longus;calycislobi2 longi,obtusi,glandulosi,albomarginati. Corollaalba;tuboloboscalycis
mm mm
aequans. Corollaelaciniae2posterioresobovato-ellipticae,7 longae,2anterioresellipticae6
mm mm
longae, 2.7 latae, e basi roseomaculatae. Labellum minutum, 0.9 longum, ovatum, 2 basi
appendiculisinstructum. Appendicesfaucis2,pegmatimorphae,intubopauloinfralaciniasposteriores
mm mm
instructae. Capsulaellipsoidea, 6 longa, 2 lata.
Typus: near Mt Madden, 40 km N of Ravensthorpe, 33° 15'S, 119° 50'E, Western Australia,
28November 1974,E.Wittwer 1507(holo: PERTH02991357;iso: CANB, K,KPBG,MEL,NSW).
370 NuytsiaVol.9,No,3(1994)
FCig-uhryepa1n,Stthyiluimdisuhmopwuilnvginiinfodrummee.nAtu-mfloofwgelrainndgupllaarnth;aiBrs-;lDeaf-ocfobraoslallar(loesfett)tsehsohwoiwnigngdeatdaaixlioafltvhireowat(r(riigghhtt))a;nEd-laetnelraalrgveidewse(cltefito)n;
ofthecorollatubeshowingledge-likeappendageinthroat;F-labellum;G-lateralviewofcolumn(left),withthestigmagrown
out(right);H-adaxialviewofcolumnandanthers(left),withthestigmagrownout(right);I-abaxialviewofcolumnshowing
antherstage(left)andstigmastage(right). Scalebar=1 mm. DrawnfromLowrie 121(PERTH).
AllenLowrieandKevinF.Kenneally,Stylidiumpulviniforme 371
Smallcaespitoseperennial, branched so asto form adense flat-topped hard cushionup toc. 30
cmdiameter. Leavessilvery grey, all basal, linear-lanceolate, glabrous, 3 mm long, 0.6 mm wide,
with a white hyaline margin, serrate near apex; lower surface carinate, the ridge hyaline like the
margins. Inflorescencescymose,3-5flowered,2.5-4.5cmhigh,denselyglandular;bractslinear, 1-2
mm mm mm
long; bracteoles 0.6 long. Hypanthium narrow-cylindrical 4.5 long, glandular-
mm
pubescent. Sepals2 long, freetobase,obtuse,glandular-pubescent,hyaline-margined. Corolla
mm mm
white,verticallypaired;tubeequalinlengthtosepals;twoanteriorlobeselliptic,6 long,2.7
widewithredmarksatthebaseofeachlobe;twoposteriorlobesobovate-elliptic,7mmlong,4mm
wide. Labellumminute,ovate,0.9mmlong,withtwobasalappendages,positionedonasmall keel-
like ridge attached along the length ofthe corolla tube. Throat with 2 appendages in the form of
mm mm
minuteledges deepinthroatbelow posteriorlobes. Capsuleellipsoid, 6 long and 2 wide.
Seeds pale, densely papillate.
Figure2. Stylidiumpulviniforme. PhotographoffloweringmaterialcultivatedattheWesternAustralian
Herbarium,grownfromplantscollectedatthetypelocalitybyE.Wittwer,November1974.
372 NuytsiaVol.9,No.3(1994)
Other specimens examined. WESTERN AUSTRALIA: Lake Johnston, 17 October 1984,
H. Demarz 10354 (KPBG); wherethePhillipsRivercrossestheHyden-Ravensthorperoad, c. 4km
NofthejunctionofFitzgeraldandBeattyRoads, 17October\99Q,AUenLowrie121 (PERTH,MEL)
and 7December 1990, Allen Lowrie 220 (PERTH); 2 miles east of Duladgin Rocks (31°10'S
119°4rE) north ofYellowdine, 2 September 1966,A./f. Main s.n. (PERTH).
Distribution. CoolgardieDistrictoftheSouth-westernInterzoneandtheRoeDistrictofSouth-west
BotanicalProvince(Beard 1980),extendingfromYellowdineinthenorthtoMtMaddeninthesouth
and eastwards to Lake Johnston.
Ecology. Thisspeciesoccursinwhitesandonthemarginsofwinterfreshwaterpoolsandinsalt-free
soilsabovethehighwaterline ofsaltlakes. Theassociatedvegetation is ashrublandofMelaleuca
thyoides Turcz. and Darwiniadiosmoides (DC.) Benth.
Flowering period. September-November.
Conservationstatus. CALMConservationCodeforWesternAustralianFlora:PriorityOne- Poorly
Known Taxa- known from one or afew (generally <5) populations which are underthreat.
Chromosome number. n=14.
Etymology. Thespecificepithetalludestothehabitofthenewspeciesinformingcoloniesofcushion-
like plants.
Discussion
The new species is distinctive, although clearly relatedto S. corymbosumR. Br. and S. lepidum
Benth. These three species are similar in having small, cymose inflorescences (not racemes), and
ledge-likethroatappendagesbornewelldowninthethroat(Erickson 1958). Stylidiumpulviniforme
differsfromS. corymbosumandS. lepiduminhaving averyshortglandularscape,veryshortleaves
withwhitehyalinemargins(serrateneartheapex)andacarinateridgeontheirabaxialsurface;white
corolla lobes, which are markedred at base, and a short ovary. Thecolumn ofS. pulviniforme is
similartothatof5.lepiduminthattheybothworkfrombelow,thepollenorstigmatouchingthelower
side ofan insect’s abdomen.
Key to Stylidiumpulviniforme and related species
1. Leaf margins entire S.corymbosum
1. Leafmargins serrate
2. Scape glabrous; labellum with apical point S. lepidum
2. Scape densely glandular hairy; labellum without apical point S. pulviniforme
The seed coats of Stylidium species appear to provide a useful taxonomic character for
identification,anditisourintentiontoexaminethisfeatureinforthcomingpublications.S.pulviniforme
has a seed coat with a densely papillate surface. (Figure 3)
AllenLowrieandKevinF.Kenneally,Stylidiumpulviniforme 373
Figure3. SEMphotographsofaseedofS.pulviniformeshowingthedenselypapillatesurface. FromLowrie220(PERTH).
Acknowledgements
We wish to thankMrs Pauline Farrell, Kings Park and Botanic Garden, Perth forchecking the
collecting details of the type material. Dr John Kuo, Electron Microscopy Centre, University of
Western Australia, kindly provided the SEM photographs and Dr S. James, Botany Department,
University ofWestern Australia, the chromosome count.
References
Beard,J.S.(1980). AnewphytogeographicmapofWesternAustralia. WesternAustralianHerbariumRes.NotesNo.3:37-58.
Erickson,Rica(1958)."Triggerplants". (PatersonBrokenshaPtyLtd:Perth.)
Milbraed, J. (1908) Stylidiaceae. In: E. Engler, (ed.) Das Planzenreich IV no.278 (35), 98 pp. (Verlag H.R. Engelmann,
Weinheim:Germany.)