NOTES ON THE MATELEA BAYATENSIS-CORRELLII-TIGRINA COMPLEX (APOCYNACEAE: ASCLEPIADOIDEAE: GONOLOBINAE) IN THE GREATER ANTILLES AND BAHAMAS

2005·3.6 MB·English

by  Alexander Krings

NOTESONTHEMATELEABAYATENSIS-CORRELLII-TIGRINA
COMPLEX(APOCYNACEAE:ASCLEPIADOIDEAE:
GONOLOBINAE)INTHEGREATERANTILLESANDBAHAMAS
AlexanderKrings
Herbarium,DepartmentofBotany
NorthCarolinaStateUniversity
RaleigtiNorthCarolina27695-7612,U.S.A.
[email protected]
ABSTRACT
AsaccimponentotalargerstudyolilicWestIndianMatelectsiibgenusP(yet;nI/ic/"(/,thisstudystuight
tocriticallyexaminepatternsol mor|iliologicalvariationwithintheembeddedM.bayalensis-
coyreUii-li^rinacomplex.Resolutionolspecies-le\'clcircumscriptionsarenecessarybelorelarger
issuesolsubgenericandgenericcircumscriptioncanbeadecjuatelyaddressed.Morphologicalchar-
acterswereanalyzedusingparsimonyanalysis,neighbor-joining,andANOVA.Resultsshowthat
Mateleiihayatensis,M.correllii,and;Vf.tigrinaareverycloselyrelatedmorphologically.Thethree
speciesappeartodilieronlyinpubcseeirceandrelativelyminorIloralcharacterstates,someolwhich
overlap.Atpresent,noneoftheobservedvariationappearsimportantenoughtowarrantthecontin-
uedrecognitionolthreedistinctspecies.
RESUMF.N
EsteestudioesuncomponentedeotromasainpliodeMatelcasubgenusPtycanlhcradelasIndias
Occidcntales,yestadedicadoaexaminarcriticamentelospatronesdevariacionmorfok\gicaencl
complejoM.hayalensis-correlUi-tiy^riiiii.Seneccsiialaresoluciondelascircunscripcionesani\'el
especificoantesdeabordarlascircunscripcionesdelosgenerosysubgenerosadecuadamenlc.los
caracteresmorlologicosseanalizaronusandoanalisisdeparsimonia,delvecinomasproximo,y
ANOVA.Losresultadosmuestranc|ucMateledbdvutensis.M.correllii,yM.tig,rinaestanmuy
relacionadosmorlologicamente.Lastresespeciesparecendiferirsoloenlapubescenciayestadosde
caracierIloralesrelativamentemenores,algunosdcloscualessesolapan.Actualmente,ningunade
lasvariacionesobservadasparecelosulicienteimportantecomoparajustiiicarelrcconocimicntode
tresespeciesdiferentes.
The Metastelmatinae-Oxypetalmae-GonolobinaecladesensuRapinietal.
(2003)isthemostmorphologicallydiverseoftheNewWorldAsclepiadeaeand
mostmembershaveneverbeenmonographed.Thecircumscriptionoftwo
Gonolobinaegenera—GonolobusMichx.andMatdeaAubl.—hasbeenparticu-
larlycomplicatedbytheswellingof thelatterbyWoodson(1941).Unableto
cometotermswiththelargevariationincoronamorphology,Woodson(1941)
submergednumerousgenerawithinMatdea,increasingitssizefromfourto
over100species.EstimatesofspeciesnumbersofGonolohusvaryfromfOOto
150(Rosatti1989;Mabberly1997;Stevens2001).Thedegreeofvariationislargely
theresultofdifferencesregardinggenericlimits,aswellasstillpoorlyknown
SIDA21(3):1525-1533.2005
1526 BRIT.ORG/SIDA21(3)
tropicaltaxa. Woodson(1941)consideredtheentirely Antillcansubgenus
Ptycanthcvdtobe"largelythedecidingfactor"forhisinclusivetreatmentof
Matelea,notingthat"wereitriotlortheAntilleanspecies,onemiglitcomposea
fairlyrespectablekeytoseveralgenerauponthecontinent."Asacomponentof
alargerstudyofM.subg.Ptycanthera,thatultimatelyseekstobearonissuesof
genericcircumscription,thisstudysoughttocriticallyexaminepatternsofmor-
phologicalvariationwithintheembeddedM.hayatensis-corrdlii-tignnacom-
plex.Resolutionofspecies-levelcircumscriptionsarenecessarybeforelarger
issuesotsubgenericandgenericcircumscriptioncanbeadequatelyaddressed.
METHODS
Basedonstudyofavailablespecimens(Table1),amatrixofmorphologicalchar-
acterstates(Tables2&3)wasdevelopedtorsevensp)eciesandsubjectedtopar-
simonyanalysisusingPAUP*(Swofford2003).BesidesMateleabayatensis(Urb.)
Woodson,M.correlliiSpellman,andM.tigrina(Griseb.)Woodson(allmem-
bersofsubg.PtycantherasensuWoodson1941),thematrixalsoincludedthree
additionalWestIndiantaxa,representingothermembersofsubg.Ptycanthera,
aswellassubg.PoicillasensuWoodson(1941).CloselyalliedtoMatelea(Rapini
etal.2003),thetypelorthegenusGouolobusMichx.(i.e.,Gonolohussubcwsus
(L.)R.Br)waschosenastheoutgroup(seealsoKrings&Xiang2004).Themor-
phologicaldatamatrix(Table2)wascomprisedofsixteenqualitativecharac-
ters.Multistatecharactersweretreatedaspolymorphisms.Bootstrapsupport
valuesweredeterminedusingthebranch-and-boundalgorithmwith10,000
replicates.Toexaminepheneticsimilarity,themorphologicalcharactermatrix
wasalsosubjectedtoNeighbor-joining(NJ)analysisusingPAUP*(Swofford
2003).Continuousdatarepresentedbypedicelandcorollalobelength,both
charactershistoricallyusedbyauthorstodelimittaxainthecomplex(see
Grisebach1863;Urban1925),werecriticallyanalyzedusingANOVA.Inall,thir-
teenherbariumsheetsot Mateleabayatensis,M.eorrelln,andM.tigrinawere
examined,afthoughonlyfourindividuafcollectionsexhibitedflowers(Table
1).Thesespecimensessentiallyrepresentthesumtotalofavailableherbarium
specimensot thegroup,asmaterialwasrequestedfromeighty-threeinstitu-
tionsknownorlikelytohousematerialofsubtribeGonolobinaeintheWest
Indies.OnlytheholotypeofM.correllii(MO),thelectotypeofM.tigrina(GOET
fideHoward1988),andasyntypeofM.tigrina(MO),werenotstudiedasthey
couldnotbeobtainedonloan.
RHSULTS
Parsimony—AnexhaustivesearchusingPAUP*(Swofford2003)evaluated945
treesandyieldedtwoofshortestlength(Length=29;Cl=0.862;Rl=0.692;Fig.1).
Nineofthesixteenmorphologicalcharacters(56%)wereparsimonyinforma-
tive.ThetwotreesareidenticalexcepttorresolutionoltheMateleabayatensis-
KRINGS,MATELEABAYATENSIS-CORRELLII-TIGRINACOMPLEX 1527
Table1.Specimensexaminedandchosenforanalysis.
SubgenusofMatelea Species Locality Source
sensuWoodson(1941)
Qonolobussuberosus SoutheasternU.S.A. Krings&Xiang(2004)
(L)R.Br.
Poicilla Mateleaovatifolia Cuba,Oriente Wright2965{SJ:G,GH,
(Griseb.)Woodson BREM.UC)
Ptycanthera Mateleabayatensis Cuba,Oriente EngStrom3056(ST:NY,S)
(Urb.)Woodson
Ptycanthera Mateleacorrellii Bahamas,LongIsland Spellman(1978),Corre//
Spellman 49//2(ITF.FTG.GH,NY,
US),Correll48157
(topotype:FTG,MO,NY);
Correll44937ifJG)
Ptycanthera Mateleaoblongata Cuba.Occidente Bntton&Wilson14867
(Griseb.)Woodson {H\),Bnttonetal.7379
{NY),Ekman17625[S),
Leon17423{m),Shafer
13508(NY)
Ptycanthera Mateleapauciflora Hispaniola EkmanH14296iS),Garcia
(Spreng.)Woodson &Pimentel2531(MO)
Ptycanthera Mateleatignna(Griseb.) Cuba,Oriente Wright/667(ST:G,GH)
Woodson
correllii-tigrinaclade.Thecladeitselfappearswell-supportedbybootstrap
values,asistheMateleaovatijolia-ohlongataclade.ThetwoCubantaxa,Matelea
bayatensisandM.tigrinaemergedneareroneanotherthaneithertoM.correlli
inoneofthetrees,althoughwithveryweakbootstrapsupport.
NJandANOV^.—Theneighbor-joining(NJ)analysisshowedtheCuban
taxa—M.bayatensisandM.tigrina—tobemoresimilartoeachotherthanei-
theristotheBahamantaxonM.correllii(Fig.2).TheNJtreeisidenticaltothe
secondoftheshortesttreesidentifiedbyparsimonyanalysis(Fig.1,B).Matelea
tigrinabearssepalsthataredenselypubescentwithbothglandularand
eglandularhairsandcorollalobesthatarepubescent(thoughnotdenselyso)
ontheabaxialsurface.Incontrast,Mateleacorrelliibearsglabrouscalycesand
corollas.Mateleabayatensisisintermediate.Itssepalsarescattered(notdensely)
pubescent,withglandularandeglandularhairs,andtheabaxialcorollalobes
areglabrous.SepalsarelanceolateinMateleabayatensisandM.tigrina,and
ovateinM.correllii.Allthreetaxainthecomplexshowstrongreticulationsof
theircorollalobes,whitedotsatthecorollalobeapices,andsimilarcoronaand
gynostegialmorphology.Althoughpedicellengthandcorollalobelengthhave
beenusedtodelimittaxainthecomplex(seeGrisebach1863;Urban1925),an
analysisofvarianceshowednostatisticallysignificantdifferenceinmean
..
1528 BRIT.ORG/SIDA21(3)
Table2.Charactersandstatesscoredfortheparsimonyandneighbor-joininganalyses.
Character State
1 Adaxialleafbladevestiture =glabrous/glabrate;1=pubescent
2.Abaxialleafbladevestiture -glabrous/glabrate;1=pubescent
3.Leafbladeapex =acuminate;1~acuteorobtuse;2=roundedor
emarginate
4.Leafbladebases =cordate;1=rounded/truncate;2-cuneale
5.Adaxialsepalvestiture =glabrous;1=pubescent
6.Abaxialsepalvestiture =glabrous;1=pubescent
7.Corollacoloration =uniformlycolored;1=reticulate;2=center
differentlycolored
8.Corollaadornment =absent;1=eachlobebearingawhitespot
apically
9.Corollalobeshape =broadlyovatetosuborbicutar;1=oblong,
triangular-deltate,orlanceolate
10.Adaxialcorollalobevestiture =glabrous;1=pubescent
11 Abaxialcorollalobevestiture =glabrous;1=pubescent
12.Cs(staminalcorona,seeKunze1995) -absentorshallow;1=well-developed,and/or
foliate
13.Stylarheadshape =flatordepressed;1=conical
14.Stylarheadappendage =absent;1=present
15.Cd(dorsalantherappendages, =absent;1=present
seeKunze1995)
16.Orientationo(polliniumcavityin =+/-horizontal;1=descending
theqynosteqialhead
pedicelorcorollalobelengthatthe95%conlidencelevel betweenthethfce
species(pedicellength:F=1.98<Fcrit=3.49;coi'ollalobelength:F=.3.b5<Fcrit
=3.86).Agraphicalrepresentationotthesedatashowsevidentoverlap(Fig.3).
ni.sciissioN
TheoldestnameintheMatelca\\\valcns,\s-corrd\\\'i\grinacomplexwaspro-
vided by Grisebach(18(^3)loraCuban taxon then relerred tothegenus
Gonolohu^:G.(igrinu.sGriseb.Urban(1925)lateraddedG.hayatcnsisUrb.tothe
complex,distinguishingitfromG.iis^nnnsbyshorterpedicels,lanceolatese-
pals(vs.elliptic-oblong)whicharescarcelypiloseabaxially(vs.pilose),and
longercorollalobes,theseovatetoovate-rotund(vs.orbicular).Astudyotthe
typesofbothtaxaquicklyshowsthesecharacterstobeproblematic(M.(it;rina:
Wright1667,G!,GH!;M.hayatcnsis:Arlh.Hngslrominherb.Fkman30,56,NY!,
S!).Urban'sinterpretationolsepalandcorollalobeshapesissubjectiveandthese
leafuresappeartointergrade.Perhapshispedicelmeasurementswerenotmade
onextantmaterial,aspedicelsontheremainingtypesare2.71-3.96mmlong
andthuswellwithintherangeol G.(ii^^rinu.sd.e.,2.6-3.69mm).Furthermore,
corolIasolG.(igr/iitrsweredescribedinCnMsebachsprotologueas5-6mmlong,
KRINGS,MATELEABAYATENSIS-CORRELLII-TIGRINACOMPLEX 1529
Gonolobiissubt'ivsiis (SEUSA)
Mateleabayaternis Ptycanthera
(CUBA)
70
Mali'kacorrellii Ptycanthera
(BAHAMAS)
70 Mateleatigrina Ptycanthera
(CUBA)
Malekaovatifolia Poici11a
68 (CUBA)
Maickaoblongata Ptycanthera
(CUBA)
A
Mateleapaucijhra Ptycanthera
(CUBA)
Gonolobussubeivsus (SEUSA)
-Mateleabayatensis Ptycanthera
30 (CUBA)
70 Mateleatigrina Ptycanthera
(CUBA)
-Mateleaeorrellii Ptycanthera
70 (BAHAMAS)
Mateleaovatifolia Poicilla
68 (CUBA)
-Malekaoblongata Ptycanthera
(CUBA)
B
•Mateleapaucijlora Ptycanthera
(CUBA)
Fig.1.Thetwoshortesttrees(A-B)resultingfromaparsimonyanalysisofmorphologicalcharacters(exhaustivesearch)
instudyoftheAntilleanH/lateleabayatensis-correllii-tigrinacomplex(eachtree:length=29;CI=0.862;Rl=0.692).
Bootstrapsupportvaluesappearabovebranches.MarginalannotationsindicatesubgenusofMateleasensuWoodson
(1941)(ifapplicable),follov\/edbygeographicdistributionofthespecies.
1530 BRIT.ORG/SIDA21(3)
Gonolobiissiiberosus
Matekabayaknsis
Matcleatigritia
MatekacomHii
Matekanvatijolia
Matekaoblongata
Matekapauciflora
Fig.2.Neighbor-joiningtreeshowingpheneticsimilarityintheAntilleanMateleabayatensis-correllii-tigrinacomplex
basedonsixteenmorphologicalcharacterstates.
8.3 5.36
_7 E 4.86
JEccZ)5 4,67 £ecEn,4 4.'138.57 -4.4 34532.76 4.12
U 3.•9336.4488 2.97 -369 JOT3O -J 2.89
D0.) 271 ?fi 2.71 o2o 2
1
1 1 1 1 1 1
Engstrom Wright Wright Correll Engstrom Wright Wright Correll
3056(NY,S) 1667 1667 49112(FTG. 3056(NY.S 1667 1667 49112(FTG,
A (G) (GH) GH,NY) B (G) (GH) GH,NY)
Specimen Specimen
Fig.3.ContinuousfloralcharactershistoricallyusedtodelimitIVIateleabayatensis,M.coneHii,and/M.tigrina:A,pedicel
length;B,corollalobelength.Measurementsindicatemaximum,mean,andminimumfromtoptobottom(inmm),
unlessonlyasinglemeasurementwasavailable.fngsfromi056=M.froyofenj/siWn^/if7667=/W.f;9™o;Corre//49n2
=M,correllii.ThetwoWrightspecimenslikelyrepresenttwodifferentindividualscollectedatdifferenttimesandlo-
calities(seeHoward1988).
1
KRINGS,MATELEABAYATENSIS-CORRELLII-TIGRINACOMPLEX 1531
Table3.Morphologicalcharactermatrixusedintheparsimonyandneighbor-joininganalysesof
theMateleabayatensis-correllii-tigrinacomplex.
Taxon Characterstates
Gonolobussuberosus {01}10001(02}01{01}110010
Mateleabayatensis 001{01}011100001000
Mateleacorrellii 0011001100001000
Mateleaoblongata 00{01){12}000010021001
Mateleaovatifolia 001{01}00000102000
Mateleapauciflora {01)1{12)1010010001100
Mateleatignna 001{01)0111001 1000
justamillimetershorterthanG.bayatensis.Whendriedbothtaxahavesimilar
corollalobelengths(to4.18mmmG.bayatensis;to4.4mminG.tigrinus)-
althoughdifferentialshrinkagehasbeenshownmotherMateleaspecies(see
Drapalik1969).Thesepalvestituretraitremainstrue.However,thisseemsin-
sufficientbasisforrecognizingtwoseparatespecies.
Withoutpublishingacriticalstudyofthecomplex,Woodson(1941)later
providednewcombinationsforbothtaxainMatelea,applyinghisconceptthat
Gonolobusshouldbecharacterizedprimarilybydorsalantherappendagesand
smooth,wmgedfollicles.Dorsalantherappendagesappeartobelackinginboth
M.tigrinaandM.bayatensis.FolliclesofthetwowereunknowntoWoodson
(1941),astheyaretodayasbothspeciesareknownonlyfromthetypespeci-
mens,noneofwhichbearfruit.However,theinterpretationofthepresenceof
dorsalantherappendagescanbedifficultfromherbariumspecimens.Atleast
SIXspeciestransferredfromGonolobustoMateleabyWoodson(1941)werecon-
sideredbySchlechter(1899)andUrban(1925)tobeardorsalantherappend-
agestosomedegree.ThecontroversialtaxafallintotwoMateleasubgenerasensu
Woodson(1941)—PachystelmaandtheAntilleanPtycanthera—mdincludeM.
bayatensisandM.tigrina.Theutilityofthefolliclecharacter(primarilywinged
inGonolobusvs.primarilymuricateinMatc/ea)isalsoproblematic.Withgreater
collectionssinceWoodson(1941),ithasbecomeclearthatseveraltaxaappar-
entlylackingdorsalantherappendagesbearwingedinsteado( muricatefol-
licles.ThesetaxaincludethemorerecentlydescribedMateleacorrelliiSpellman
(1978)fromtheBahamas,whichbearsextremeresemblanceinhabit,foliar,and
floralcharacterstoM.bayatensisandM.tigrina.
Mateleabayatensis,M.correllii,andM.tigrinaareclearlycloselyrelated
morphologically(Figs.1-3).Thethreetaxaappeartodifferonlyinpubescence
andrelativelyminorfloralcharacterstates,someofwhichoverlap(Fig.3).This
minorvariationmaybeduetotheverylimitednumberofcollectionsandmight
becompletelyindistinctifmorecollectionswereavailable.Flowersizes(includ-
ingpedicellengths)canlikelybeinfluencedbygrowingconditions,ascan
1532 BRIT.ORG/SIDA21{3)
pubescence.Atpresent,noneoftheobservedvariationappearsimportant
enoughtowarrantthecontinuedrecognitionofthreedistinctspecies.Atthe
least,basedoncurrentevidence(all^eithmited),thetwoCubanspecies—Maiclea
hayalensisandMatekatigrina—canbeconsideredsynonymous.Considering
geographicdistribution,thattheCubantaxaappearmorecloselyrelatedtoeach
otherthaneachistotheBahamantax'on,andthatGonolohustigrinusisthe
oldestbasionym,italsoseemsappropriatetotreattheBahamantaxonasasub-
specieswithinMatelcatigriuu.Thequestionofwlietlierthespeciesshouldbe
relerredtoGonolohuscannotyetbeansweredbasedonthematerialathand.
On-goingworktowardarobust phytogenybasedonmoleculardataaimsto
addressthisquestion.Untilthen,newcombinationsareavoidedtolimitun-
necessarynames.
TAXONOM1CTRFATMENT
Maieleatigrina(Griseb.)Woodson,Ann.MissouriBot.Card.28:226.1941.Conolohus
ti^^rinu.'.Cn-iscb.Mcm.Aiiicr.Acad.Artssen2,8:520.1863,Tyi'I-::CUBA:Wrij;ii(1667.1860(LEC-
TOTYl'i-::GOHTindcl-lowardK)88);SYNTVPHS:MOlimagconline!],G!,GH!).
G()H()li)i!U.sl)i;iy(itensisUrb.,Symb.Antill.9(3):420-421.1925.Isynon.nov.lMcifdeahayatcnsi^dUh.)
Woodson,Ann.MissouriBot.Gard28:226,1941.TYPE:CUBA:Arth./int^'.s'lrOminherb,likman
n.3056(SYNTYIT.S:NY!.S!).
MaidcaiodcUuSpellman.Ann,MissouriBot.Gard,65:1255-1257,1978,[synon,nov,|Typi::BA-
HAMAS.I.ONt,LSI.AND:ns.Condi49112(l\0\otypi-:MO;Lstriyphs;P!,FTG!,GH!,NY!,t!S!)
Distribution—TheputativesubspecificentitycomprisedbyM.tignnaandM.
ki}/dtcn,sj,sisapparentlyrestrictedtoCuba.Theputativesubspecificentitycom-
prisedbyM.corrclliiisapparentlyendemictotheBahamas.
Notes.—Spellman's(1978)noteofaresemblancebetweenM.convUiiand
M.grisebachiana(Schltr)Alain ispuzzlingasthelatterwasdescribedwith
leavesonly to0.7cm wide(initiallydescribedasGonolohustignnusvar
angustifoliusGriseb.)andoblongcorollalobes.LeavesofM.corrclliiaverage
1.5-2.5cmdiam.Schlechter(1899)alsonoteddifferencesbetweenM.tigrina
andM.gnschachianaintheoutercoronaandmthepresenceofconspicuous
dorsalantherappendages('Cd'sensuKunze1995)inthelatterUnfortunately,
thetypeofM.grisehachiana(Cuba,Wrights.n.)hasnotyetbeenlocatedand
mayhavebeendestroyed.AdditionalspecimensofM.grisehachianahavealso
notbeenlocatedandcouldthusnotbeanalyzed.
ACKNOWLEDGMl-NT.S
1thankthecuratorsandstaffofthefollowingherbariaforaccesstotheircol-
lectionsorloansofspecimens:BM,BM,BOLO,BRF.M,C,CGf:,DUKE,E,F,El,FR,
FTG,G,GH,GOEXH,HAG,ITAJB,1IBG,IJ,JE,K,M,MlClI,MIN,MO,NY,O,
OXFP,PH,RSA,S,U,UC,US,USEWU,Z.Ialsothankthecuratorsandstaffof
the lollowing herbaria lor searching theircollections for West Indian
KRINGS,MATELEABAYATENSIS-CORRELLII-TIGRINACOMPLEX 1533
Gonolobinaematerial,althoughfindingnorepresentation:BG,BKL,BR,BUF,
COLO,CR,FLAS,lA,ISC,LD,MSU,NEU,NSW,UPS,TUR.Theassistanceofthe
NorthCarolinaStateUniversityLibrariesInter-LibraryLoanServiceisalso
gratefullyacknowledged,asarethemanuscriptreviewsbyBruceHansenand
JustinWilliams.
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