A new species of Nicotiana (Solanaceae) from near Broome, Western Australia

5 Pages·1994·1.5 MB·English

by  D E Symon

Nuytsia9(3): 421-425(1994) 421
A newspecies ofNicotiana (Solanaceae) from nearBroome,
Western Australia
D.E. Symon'andKevinF. Kenneally^
1 C/-TheBotanicGardensofAdelaideandStateHerbarium,NorthTerrace, Adelaide,SouthAustralia5000
2WesternAustralian Herbarium,DepartmentofConservationandLandManagement,
POBox 104,Como,WesternAustralia6152
Abstract
Symon, D.E. and Kenneally, Kevin F. A new species of Nicotiana (Solanaceae) from near
Broome, Western Australia. Nuytsia 9 (3): 421-425 (1994). Nicotiana heterantha Symon &
KenneallyisdescribedfromnearBroome,WesternAustralia. Thenewspeciesisknownfromonly
two populations, both of which are under threat from grazing. It appears most closely related to
N. rosulatasubsp. rosulata.
Introduction
AnewspeciesofNicotiana,namelyN. heterantha,aKimberleyendemicisdescribedinorderto
validatethenameforuseinaforthcomingbookontheplantsofBroomeandtheDampierPeninsula.
TherehavebeenthreeaccountsofNicotianainAustraliainrecenttimes. Apioneeringaccountby
Burbidge(1960)broughttogetherrecordsuptothatdateanddescribedfivenewspeciesandtwonew
subspecies. ThiswasfollowedbyHorton(1981)whodescribedtwonewsubspeciesand reducedone
ofBurbidge'sspecies(N. hesperis)totherankofsubspecies. TheacountofNicotianaintheFloraof
Australia,Purdieetal. (1982) wasbasedon Horton. Sincethen Symon (1984)hasdescribedanew
species, N. burbidgei from near Dalhousie Springs in the far north-east of South Australia, and
Clarkson & Symon (1991)describedN. wuttkeifromnorth-easternQueensland.
Taxonomy
NicotianaheteranthaSymon &Kenneally, sp. nov. (Figure 1)
Herba annua decumbens, pilis simplicibus et glandulosis. Folia radicalia petiolata; laminae
ellipticae vel obovatae ad basim attenuatae; apices obtusi. Folia caulina ex axillis caespitosa.
Inflorescentiaracemosa,filometallicosimilis;bractisparvis;floresinterdumcleistogamae. Calyx7-9
mmlongus,lobissubaequalibus,apicibus triangularibus. Corollaminutepubescens; tubus2.5 cm
422 NuytsiaVol.9,No.3(1994)
Figure1. Nicotianaheterantha A-floweringplant(scalebar=4cm), B-corollaofchasmogamousflower(scalebar=1.75
cm),C-budofcleistogamousflower,D-corollaofcleistogamousflower, (CandDscalebar=4mm),E-capsule(scalebar
=4.5mm), F-seeds(scalebar=0.5mm). DrawnfromapotplantgrownfromseedofKenneally 11338.
1
D.E. Symonand K.F. Kenneally, Nicotianaheterantha 423
longus;limbus0.7-1cmlongus;lobilimbiemarginati. Staminaquattorsubdidynamainfauci,quintum
brevi filamento semiadnatum. Capsula ellipsoidea 8-10 mm longa. Semina angularia reniformia
brunneareticulata.
Typus: Buckleys Bore, 11 km N of Broome, Dampier Peninsula, 17° 5rS, 122° 13'E, Western
Australia,J.B. Martin 225, 8Mar. 1992 (holo: PERTH2169819;iso: AD,CANB, K).
Annualorshort-livedperennialherb,branchingnearthebase. Decumbentstemsdeveloptuftsof
leaves atthelowernodes. Leavesatfirstbasal, 2-10x 1-4.5cm,commonlyc. 7x 2.5 cm, petiolate,
elliptic to obovate, apex obtuse, base attenuate, margin entire, petiole 2-2.5 cm, narrowly winged,
attachmenttostemsimple. Leavesatfirstbasalandeauline,theseintimereplacedbytuftsofleaves
at the stem nodes and in the lower parts ofthe inflorescence. Indumentum ofsimple and minute
globular-headed glandularhairs, more common on youngparts andcalyces but neverconspicuous,
leaves and wiry stems glabrescent. Inflorescence a simple or sparsely branched raceme, the axis
relatively slenderandwiry, to 1 m long, decumbent. Stem leaves soon reducedto linear-triangular
mm
bracts3-5 long, tuftsofleavesdevelopatthe lowernodes (seeabove),from theseaxillarytufts
ofleaves short flowering axes 1-5 cm long with 2-5 flowers may develop; pedicel c. 7 mm long.
Chasmogamousflowers{Kenneally1 2>2>%):calyx7-9mmlong,thelobesjoinedbymembrane2-3mm,
thelobesfreefor2mm, lobeapextriangular,allminutelyglandularpubescentwithinthelowerhalf,
limb0.7-1 cm long,dividedabouthalfway, lobeapexemarginate. Fourupperanthersonfilaments
1.5-2mmlong,thelowerfifthantheronfilament6-7mmlong. Anthers 1mmlong;yiy/e2.8cmlong;
stigma capitate, exsertedjust beyond the four anthers. Ovary 2 mm, conical, sparsely minutely
glandularpubescent,basesurroundedbycircularfleshydisc. Cleistogamousflowers:calyxasabove
mm mm
butcorollatubeandlobesc. 5 long,notexpanding. Capsulec. 8-10 long,apexacute,equal
toorexceedingthecalyx,dividingtofourvalveswhenmature,thecalyxtubeandcapsuleoftenslightly
constricted at aboutone-quarter oftheirlength, the lower quarter somewhat thicker and hardened.
mm
Seedsto1 long,bluntlytriangulartoangularlyreniform,reticulatewithsharp-edgedwavyridges,
thecellsdeeply concave,brown.
Otherspecimensexamined. WESTERNAUSTRALIA: CoconutWell, 15kmNofBroome, 10May
1985, Foulkes 237 (AD, CANB, K, PERTH); Coconut Well, 15 km N ofBroome, 17 June 1984,
K.F. Kenneally9031 (CANB,PERTH);BuckleysPlain, 10kmNofBroome, behindO.T.C. station,
1 Sept. 1992,Kenneally 11338 (PERTH); BuckleysPlain O.T.C. side, 7 kmNofBroome,Dampier
Peninsula, 17°54'S, 122°15’E,24April 1992, Martin226(PERTH).
Distribution. This istheonlyNicotianasofarcollectedfromnearBroome. Itformslowspreading
coloniesinandoutofMelaleucathicketsonseasonallywetblackclayinanareaknownasBuckleys
Plain northofBroometoaboutCoconutWell. (Figure2)
Floweringperiod. May-June. Thespeciesisfacultativelycleistogamous. Somespecimenscollected
inthefieldclearlyhavewelldevelopedandopencorollas,othershavereducedcorollas. Severalplants
cultivatedinAdelaideduringthesummers werecleistogamousandsignsofthecorolla werescarcely
visible. Thecauseofthesevariationsisnotknown.
Affinities. ThenewspeciesappearsmostcloselyrelatedtoNicotianarosulatasubsp.rosulata,thishas
more erect, stouterinflorescences which are morebranched above and hence the flowers are more
concentratedontheterminalpartsofthe stems. However, there areafew specimensofN. rosulata
suhsp.rosulata atADandPERTHwithfloweringaxes equallyslendertothenewspecies. Thenearest
424 NuytsiaVol.9,No. 3(1994)
Figure2. Nicotianaheterantha forminglowspreadingcolonie.sonblackclayontheedgeofaMelaleucaacacioides
thicketon BuckleysPlainnorthofBroome.
collection of N. rosulata to the new species is one from Pardoo about 4(X) km to the southwest.
N. heteranthadiffersfromallotherAustralianspeciesexcept N. debneyiinitschromosomenumber
(see below). In addition the mostly cleistogamous flowers, tufted growth, and slender wiry stems
distinguishitfromallotherAustralianspecies.
Notes. Theaxillarytuftsofleavesdevelopingatthelowernodesoftheinflorescencesandtheirshort
racemesofflowers areunusualfeaturesdistinguishingthisspecies.
Chromosome number. 2n = 48 (from Kenneally 11338). Root tips counted by Dr D.L. Hayman,
GeneticsDepartment,UniversityofAdelaide. DrHaymancommentsthat thepresenceofonly one
pairofchromosomeswithobvious nucleolarorganisingregionssuggeststhatitisan allopolyploid.
ThebasechromosomenumberforthegenusNicotianaisx=12andallAmericanspecieshavethis
ormultiplesofit(Goodspeed 1954). TheonlypreviousAustralianspecieswithmultipleofx=12were
thetwosubspeciesofN.debneyi n=24,2n=48andhenceatetraploid (Horton 1981). N. debneyi
,
occurs in eastern Australiaand is theonly Australian species toextendtoNewCaledoniaandLord
Howe Island. Although the ecology of N. heterantha is similar to that of N. debneyi subsp.
monoschizocarpa, theplantsdifferinmanycharacters. AllotherAustralianspecieshavealongseries
ofaneuploid numbersrangingfromN. cavicolan =23 toN. wuttkein= 14.
Thisnumber2n=48separatesN.heteranthafromN.rosulata2n=40inadditiontomorphological
differences.
D.E. Symonand K.F. Kenneally, Nicotianaheterantha 425
Conservationstatus. CALMConservationCodesforWesternAustralianFlora:PriorityOne-Poorly
KnownTaxa. This speciesisknownfromonly twopopulations inthesamearea,both ofwhich are
underthreatfromgrazing.
Etymology. FromtheGreekhetero-differentandanthos-flower,inreferencetothetwodistincttypes
offlowersfoundinthisspecies.
Acknowledgements
TheassistanceofBromeBotanicalSocietymembersBrianCarter,PaulFoulkes,JohnMartinand
TimWillinginobtainingmaterialandmakingfieldobservationsofNicotianaheteranthaisgratefully
acknowledged.
References
Burbidge,N.T.(1960). TheAustralianspeciesofNicotiana L. Solanaceae. Austral.J.Bot. 8: 342-378.
Clarkson,J.R.&Symon,D.E.(1991). Nicotianawuttkei(Solanaceae),anewspeciesfromnorth-easternQueenslandwithan
unusual chromosomenumber. Austrobaileya3: 389-392.
Goodspeed,T.H.(1954). ThegenusNicotiana. ChronicaBotanica,Vol. 16.
Horton.P(1981). AtaxonomicrevisionofNicotiana(Solanaceae)inAustralia.J. AdelaideBot.Card. 3: 1-56.
Purdie,R.W.,Symon,D.E. &Haegi,L.(1982). Solanaceae. FI.Austral.29:38-57.
Symon,D.E.(1984).AnewspeciesofNicotiana(Solanaceae)fromDalhousieSprings,SouthAustralia, J.AdelaideBot.Card.
7; 117-121.