Stypandra jamesii (Phormiaceae), a new Western Australian species endemic to granite outcrops

3 Pages·1999·0.86 MB·

by  S D Hopper

3
Nuytsia 1 (1):247-249(1999) 247
Stypandrajamesii(Phormiaceae),anewWesternAustralianspecies
endemictograniteoutcrops
Blindgrass orNodding Blue Lily, as presently conceived (Henderson 1987), comprises a single
variable species in amonotypic genus. Stypandraglauca R.Br. occurs in south-western and south-
easternAustralia,andpossiblyinNewCaledonia,embracingaconsiderablediversityofgrowthforms,
from large erectbamboo-likeclumps up to 2 mtall, to prostrate sprawlingherbs. All have nodding
flowers,usuallyroyalblue,butsometimeswhitealongtheDarlingRangenearPerthandnearHyden.
SomepopulationsinsouthernWesternAustraliaarepoisonous,causingblindnesstolivestockifeaten.
No suchpoisonousattributesare knownfrom the south-east.
Chromosome numbers in Stypandra glauca were documented by Keighery (1984), Henderson
(1987),andRussell(1988),thelatterinanhonoursresearchprojectsupervisedbyAssociateProfessor
SidJamesofTheUniversityofWesternAustralia. Populationswith8and 16pairsofchromosomes
occurinsouth-westernAustralia,whilecountsofonly8pairshavebeenrecordedfromplantsinsouth-
easternQueenslandandintheAustralianCapitalTerritorynearCanberra. Thisgeographicalpattern
suggests that 8 pairs is the ancestral numberofthecomplex.
Withinsouth-westernAustralia,thereisnocleargeographicalseparationofpopulationswith8and
16pairsofchromosomes. Withonepossibleexception(SullivanRock),nocasewasfoundwhereboth
chromosomenumbersoccurredtogetheramongplantson thesamerock. Bothchromosomenumber
racesextendfromgranitesintheDarlingRangenearPerth,eastwardsthroughthewheatbelt,andalong
thesouthcoastonoutcropsbetweenAlbanyandBremerBay. Polyploidymaybearecurrentsolution
tothegeneticdifficultiesposedbyinbreedinginsmallisolatedpopulationsofStypandraglaucawith
theancestral 8pairsofchromosomes. Russell (1988) foundthat substantial levelsofpollen sterility
occurin thespecies, possiblyduetoinbreedingeffects. Heproposedthatpolyploidymaskssomeof
the genes causing lethality and restores fertility. A detailed study of population relationships in
DNA
Stypandraglaucausing markerswouldenableaclearunderstandingofevolutionaryprocesses
leading to thecomplex variation shown by this widespread granite outcrop perennial herb.
Thechromosomalvariationinsouth-westpopulationsofStypandraglauca ismatchedbycomplex
morphological variation. Henderson (1987) summarized the situation succinctly:
“An extremely variable species which on presently available herbarium material cannot
unequivocallybesubdivided, thoughextremeformsareverydistinctive. Somehavebeentreated
asspeciesbutmanyspecimensshowintermediatecharactersorbothstatesofso-calleddistinctions.
W.A. material (orpartsofit) may besubspecifically orspecifically distinctfromeasternand
south-eastern material. ... The names Stypandra imbricata and .S', grandiflora were applied to
youngorold±lowplantswithmediumtobroadleaflaminasinsouth-westernW.A. S. virgata was
;
appliedtoolder,tallerplantswithnarrowleaflaminasandS.scoparia tooldtallplantswithshort
filiform leaves in this same region. 5. propinqua, applied to young plants with comparatively
narrowleaves,andS.latifolia,toyoungplantswithverybroadleavesoccurringineasternAustralia,
are unquestionably synonyms ofS. glauca.”
My own field studies over the past two decades support Henderson’s views on morphological
variationinStypandraglauca. Populationstendtobeofauniformmorphology,age-relatedfeatures
aside,butsubstantialvariationoccursfromrocktorockasonemovesacrossthesouth-westAustralian
:
248 Nuytsia Vol. 13, No. 1 (1999)
landscape. There may be a geographical basis to some ofthis variation, but rigorous quantitative
studiesareneededtoresolvethesituation. However,thereisoneatypicalvariantongraniteoutcrops
in the eastern wheatbelt, first collected by ProfessorRobertOmduffin 1983 and then by Associate
ProfessorSidJamesin 1988. Thisvarianthassmallwhiteflowers,asprawlinghabit,andissympatric
with larger erect blue-flowered specimens, thicker stemmed and smaller leaved, typical of many
populations of Stypandra glauca. No intermediates have been found where these two taxa are
sympatric. Consequently, Iregardthis white-floweredeffuse taxon as adistinctspecies.
StypandrajamesiiHopper,sp. nov.
AS.glauca R. Br.cauliaeffusiagracilioribus,floribusminoribuscremeisetanthericaminoribus,
differt.
Typus: Wave Rock [Hyden Rock], Western Australia, 12 October 1991, W. Greater 22709 holo
(
PERTH03456668).
m
Effuse,sprawlingrhizomatousperennialherb;rootsfibrous;tuftstomorethan 1 acrossatbase;
aerialstemsto30cmhigh,thin,toc. 1 mmdiameter,elongated,leafythroughout. Leavesnumerous,
ascending, soft,linear, 2-15cmlong,to3mmwide, base sheathing,cylindrical thenequitantabove,
apexacute. Upperbractslinear-subulate, 1-2.5cmlong. Inflorescenceterminal,open,cymose,few-
mm
flowered. Flowers actinomorphic, nodding to erect, on slender pedicels 3-18 long. Perianth
creamy white; segments 6, free, subequal, spreading, broadly linear, to 5 x 2 mm, usually 5-nerved.
Stamens6, shorterthan perianth, 2-3 mm long; filaments slender, becoming kinked below middle,
densely hairy distally; anthers slender,yellow,±tapered upwards, dehiscing longitudinally by slits,
mm
recurved orcoiled afterdehiscence, c. 1 long beforecoiling. Ovary superior, c. 1 long. Style
mm
filiform, 2-3 long; stigmaminute, papillose. Capsulenotseen.
Specimens examined. WESTERN AUSTRALIA; Hyden Rock, 18 Oct. 1989, S.D. Hopper 7704
(PERTH);GrahamRock, 17kmEofHyden, 1 Oct. 1990,S.D.Hopper7861 (PERTH);GrahamRock,
late Sep. 1988, S.H. Jamesfor J. Russell 35 (PERTH); Hyden Rock, 4 Oct. 1983, R. Omduff
9307-74(PERTH).
Distribution.KnownonlyfromHydenRockandGrahamRockoveranarrow 15kmrangeintheeastern
wheatbeltofsouth-western Australia.
Habitat. Grows in partial shadeon the marginsofAllocasuarina huegeliana low woodlands and in
openlowscrubatthebaseof,orinshallowsoilpocketson,largegraniteinselbergs. Associatedspecies
include Leptospermum erubescens, Dodonaea viscosa subsp. attenuata, Melaleuca elliptica,
Thryptomene australis. Acacia lasiocalyx. Eucalyptus loxophleba subsp. loxophleba, Cheilanthes
austrotenuifolia, Spartochloa scirpoidea and Santalum acuminatum.
Phenology. Flowers in October, possibly into November.
Conservationstatus. CALMConservationCodesforWestern AustralianFlora: PriorityTwo.
Etymology. Named for the late Associate Professor Sidney H. James, my respected mentor, Ph.D.
supervisor, and friend, for his outstanding research on the evolutionary genetics of the Western
S.D. Hopper, Stypandra jamesii, a new Western Australian species 249
Australian flora, and his fine abilities to inspire generations ofstudents (Hopper 1996). Stypandra
jamesii wascollectedbySid, whomostprobablyrecognizeditasnew,giventhathemaderelatively
few herbarium collections and considered this taxon importantenough to do so.
Notes.StypandrajamesiidiffersfromS.glauca mostnoticablyinitssprawlinglowhabit,effusethinner
lesswoodystems,longnarrowleavesanditssmallerconsistentlycreamflowers. ElsewhereIhaveseen
effusesprawlinglong-leavedplantsofS. glaucaonly nearCatabyinsandy soilsbeneathEucalyptus
wandoo woodland and on the Swan Coastal Plain in Eucalyptus gomphocephala woodland
(e.g.J. Russell34), butthese plantsretained the largerblue flowers typical ofthe species. Usually,
S.glaucahaserectstems,likeminiaturebamboo,upto2mtall. Thewhite-floweredvariantsofS.glauca
onthe Darling Scarpretain thistypical habit, andhave largerflowers than thoseofS.jamesii.
ThetwospeciesaresympatricatHydenRockandGrahamRock,whereS.glauca hastypicallarge
blueflowerswithperianthsegmantsto10x3mm,shorterleavesto8cmx 1mm,anderectrobuststems
to4mmdiameterand2mtall. Nohybridshavebeenfoundonthesetwoinselbergs,indicatingstrong
geneticisolationbetweenS.jamesiiandS.glauca. ThechromosomenumberofS.jamesiiisunknown.
Separate collections of both Stypandrajamesii and S. glauca were made at Hyden Rock by
ProfessorRobertOrnduffin 1983(R. Orndujf9307-74and9309-32)andbyProfessorW.Greuterin
1991 [W. Greuter22709and22708). Thissuggestsindependentrecognitionofdistincttaxabythese
botanists,aconclusionIdrewandannotatedonspecimensinOctober 1989. Undoubtedly,additional
taxaareevident in Western AustralianS. glaucacollections. The complex merits furtherstudy.
References
Henderson, R.J.F. (1987). Stypandra. In: “Flora of Australia.” Vol. 45, pp. 225-228.
Hopper, S.D. (1996). Associate Professor S.H. James - tribute to a plant population geneticist. In: Hopper, S.D.,
Chappill, J.A., Harvey MS. & George A.S. (eds) “Gondwanan Heritage: Past, present and future of the Western
Australian Biota.” pp. 53-60. (Surrey Beatty & Sons, Chipping Norton: New South Wales.)
Keighery, G.J. (1984). Chromosome numbers of Australian Liliaceae. Feddes Repertorium 95: 523-532.
Russell,J. (1988). Abiosystematic analysisofStypandraglaucain Western Australia. B.Sc. (Hons) thesis.The University
of Western Australia.
StephenD.Hopper
Botanic Gardens and Parks Authority, Kings Park and Botanic Garden, West Perth,
Western Australia6005