POLYPHYLY OF THE GENUS ECHUES (APOCYNACEAE: APOCYNOIDEAE: ECHITEAE): EVIDENCE BASED ON A MORPHOLOGICAL CLADISTIC ANALYSIS

2004·6 MB·English

by  Justin K Williams

POLYPHYLYOFTHEGENUSECHITES(APOCYNACEAE:
APOCYNOIDEAE:ECHITEAE);EVIDENCEBASEDONA
MORPHOLOGICALCLADISTICANALYSIS
Justin K.Williams
DepartmentofBioloigicalSciences
SamHoustonStateUniversity
Huntsville,Texas77341-2/i6,U.S.A.
ABSTRACT
AcladisticanalysiswasperformedtotestthemonophylyofHchites(Apocynaceae:Apocynoideae:
EchiteaeJ.Fortheanalysis40morphologicalcharacterswerecodedfor42ingrouptaxa(22genera)
andthreeoutgroupspecies(twogenera).TheresultsindicatethatEchitesascurrentlycircumscribed
ispolyphyletic.However,speciesthatfallwithintheoriginaldescriptionsofthetwosubgenerade-
scribedinEchitesforminonophyleticclades.
KeyW(iRtis:Echites,Prestonia,Theininiia,andTheveticiApocynaceae,cladistics,morphology,
Neo-tropics
RHSUMEN
Serealizounanalisiscladisticoparacomprobarlamonofiliadehe/lites(Apocynaceae:Apocynoideae:
Echiteae).Paraelanalisissecodificaron40caracteresmorfoicigicosde42taxadelgrupo(22generos)
ytresespeciescomooutgroup(dosgeneros).LosresultadosindicanqueEchitestalcomose
circunscnbenormalmentcespolifiletico.Smembargo,lasespeciesqueestanenlasdescripciones
onginalcsdclosdossubgenerosdescritosenluhitcsformancladosmonofileticos.
EchitesP.BrownewasoneofthefirstNeo-tropicalApocynaceaegeneraestab-
lished.Consequently,itservedasthelocalpointforthemajorityofspeciesde-
scribedintheNeo-tropics.Thusbythemidnmeteen-hundredstherewereabout
375speciesofEchitesdescribed.Woodson(1936Jeventuallyclearedmuchof
thenomenclaturalconfusionpresentedbythe300plusnames.Inhismonu-
mentaltreatise,Woodsonattributedtheepithetstoanappropriategenus(both
newlydescribedandpreexisting)andorsynonym,recognizingthatthespe-
ciesofEchitessensulatorepresentedmorethanninedifferentgenera.Witha
foundationestablished,Woodson(1936,1938)definedEchitessensuWoodson
byitstwininghabit,glabroussalverformcorollaswithoutcorona,included
anthers,andasolitarycoUeteroppositeeachofthefivesepals.Woodson(ibid)
ultimatelyrecognizedsevenspeciesinthegenusthatwereplacedintotwosub-
genera.
SubgenusEchitesischaracterizedbyhavingcorollas5-8cmlong,oblique
corollalobesspreadingatanthesis,andcompactinflorescencewith3-7flow-
ers(Morales1997;Williams2002a).Todayfourspeciesarerecognizedinsubg.
SIDA21(1):117-131.2004
113 BRIT.ORG/SIDA21(1)
Echites:E.danenensisJ.F.Morales,£.turrigcraWoodson,E.umhellatajacq.and
E.yucatanensisMillsp.(Morales1997;Williams2002a).
SubgenusPsucdechilesWoodsonischaracterizedbyhavingcorollas1.25-
2,5mlong,narrowlylanceolatecorollalobesthatarereflexedatanthesisanda
laxinflorescencewith8-20flowers(Woodson1936).Woodsonincludedtwo
speciesinthesubgenus:EtuxtiensisStandi,andE.iurhinataWoodson.Athird
speciesofsubg.PseudechiteswassubsequentlydescribedbyMonachino(1959):
EchiteswoodsonianaMonac.Thisspecieswouldlatercometohaveaninter-
twininghistorywithPrestoniasectCoalUae(explainedbelow).
Woodson (1936)divided Prestonia intofour sections: Coalitaeand
Acuti/oliae,(bothcharacterizedbyhavingsmallandinconspicuoussepalssimi-
lartothoseofEchites);andAnnulnresandTomentosae(bothcharacterizedby
largefoliaceoussepals).Woodson(1931,1936)includedPrestoniaagglutmata
(Jacq.)Woodsoni=Echitesagglutinata]acq.)inPrestoniasect.Coalitae.Section
CoalitaewasdistinguishedfromtheotherthreesectionsofPrestoniabyitslack
ofanannularcoronaatthemouthofthecorolla.Woodson(1960)wouldlater
describeasecondspeciesmsect.Coalitae(P.caudataWoodson).LaterGentry
(1983)transferredEchiteswoodsonianaMonac.toPrestonia(P.woodsoniana
(Monac.)Gentry)placingitasamemberofsect.Coalitae.Becauseofthecon-
fusingnatureofgenericdelimitationintheApocynaceae,andthelackofan
annularcoronainE.woodsoniana,Gentry(ibid)wasnotconfidentofhistrans-
ferJ.K.Williams(1996)maintainedE.woodsonianainEchitesbecauseitlacked
anannularcoronaatthemouthofthecorolla.Morales(1997)wouldlaterin-
cludeallspeciesofPrestoniasect.CoalitaeinEchitesstatingthatthe"narrowly
elliptictoalmostfiliformcorollalobes[ofthethreespecies]...characterizeEchites
subg.Pseudechites'\
TheinterminglinghistoryofEchitessubg.PseudechitesandPrestoniasect.
Coalitaeindicatestheproblemstaxonomistshavehadindefininggenerain
theApocynaceae.Echitessubg.Pseudechitesisataxonthatsuperficiallyre-
semblesPrestoniasectionCoalitae,whichmakeitsplacementwithinthefam-
ilydifficult.
Acladisticanalysisusingmorphologicalcharacterswasperlormedwith
twomainobjectives:1)toassessthemonophylyofEchitessensuWoodsonand
2)toidentifytheplacementandsistertaxonofsubg.Pseudechites.
N4ATERIA1,SAN13MHTHODS
—
Taxa analyzed. Included in thisanalysisare representative generaof
.ApocynoideaeknownfromMexicoandCentralAmerica.Inaddition,OldWorld
generahavebeenincludedinthestudymordertoexpandthemorphological
variationandbroadgeographicrangeoftheApocynoideae.1didnotintendto
testthemonophylyofthetribesrecognizedwithintheApocynoideae,whichis
whyalargersamplingofgenerawasnotincluded.However,thegenerathat
WILLIAMS,EVIDENCEFORANEWNEOTROPICALGENUSOFAPOaNACEAE 119
wereselectedrepresentfour(Apocyneae,Echiteae,Mesechiteae,andWrightieae)
ofthefivetribesintheApocynoideaerecognizedbyEndress&Bruyns(2000).
ThevetiaL.andCerheraL.wereselectedasoutgroupsfortheanalysis.In
previouscladisticstudies{Endressetal.1996;Sennblad&Bremer1996;Sennblad
etal.1998;Potgieter&Albert2001)Thevetiawasindicatedasoneofthecloser
relatSievleescttoiotnheofApcohacryancotierdse.a—e,Aantodtailsaopfpr4o5prtaixaat,erfeoprrreosoetnitnigngth2e5trgeeen.era,were
includedinthepresentstudy.Fortycharacters,representing105characterstates
(Table1),werescoredforeverytaxonpresentedinthisanalysis.Characterstates
wereselectedfromthoseutilizedinpreviousstudies(Struweetal.1994;En-
dressetal.1996;Sennbladetal.1998;Potgieter&Albert,2001;Williams2002b).
Newcharactersnotincludedintheaboveworks,butuncoveredduringthe
courseofthisstudywerealsoincluded.Fifteenofthecharacterswerevegeta-
tiveandtheother25werefloralorreproductive.Analysisindicatesthatnone
ofthecharactersareuninformative.Thecharactersandtheirrationalearedis-
cussedmAppe—ndix1.
Sampling. Charactermeasurementsandstatesforthedatamatrix(Table
2)wereobtainedfromherbariumsheets(specimensandlabeldata)andfield
observationsforeveryrepresentativespeciesincludedinthisstudyexcept
Tintinnahulariagratissima].¥.Morales,andfourspeciesofParsonsiaR.Br(P.
heterophylla;P.latijolia(Benth.)S.TBlake;P.praeruptisHeads&deLange;P.
purpuniscensJB.Williams).DataforT.gratissimawasobtainedfromMorales
(1996).ThespeciesofParsonsiawereincludedinthestudymordertobetter
representthediversityofParsonsia(agenuswithmanysuperficialsimilarities
toThenardiaH.B.K.).MorphologicaldataforthefourspeciesofParsonsiawere
obtainedfromliteraturedescriptions(J.B.Williams1996;Heads&deLange
1998).
WiththeexceptionofthespeciesofParsonsia,andTintinnahulariagratissima,
arepresentativespecimenisdepositedatthePlantResourcesCenter(TEX)for
eachofthespeciesexaminedinthemorphologicalcladisticanalysis.Eurther
observationsanddatawerecollectedfrommaterialborrowedfromorobserved
atthefollowingherbaria:BM,BRITCHAPA,F,FLAS,G,GH,K,MA,METPEC,
MEXU,MO,NY,P,SHSTTAMU,TEX,US,WIS.
Thepollenofallgenerawasstudiedusingalightmicroscopeaswellasa
scanningelectronmicroscope(Philips515).Allgenerawereexaminedandmea-
suredunderthe5EMattheCellResearchCenteroftheUniversityofTexasat
Austin.
—
Cladisticanalysis. Thecharactersandcharacterstates(Table2)usedin
theanalysiswereenteredintoadatamatrixusingMacClade3.0(Maddison&
Maddison1992).AphylogeneticanalysiswasthenperformedinPAUP3.1
(Swoffordf993).Aheuristicsearchbystepwiseadditionofrandomtreeswas
performedwith100replicatesandtheACCTRAN,MULPARSandTBRoptions
120 BRIT.ORG/SIDA21(1)
Table1.Charactersandcharacterstatesusedinthecladisticanalysis.
1. Latex 14. Corollacolor
O-milky 0-white
1-watery 1-yellow
2. Predominategrowthhabit 2-maroon
0-wc)C)dyshrub 15. Corollawithepistaminalappendages
1-liana 0-absent
2-suffrutico5eherb 1-reducedtoacallusedridge
3-herb 2-extendedIntoalinearprotuberance
3. Leafarrangement resemblingafilament
O-opposite 16. Coronabetweenpetalsinuses
1-alternate 0-absent
4. Colletersaroundthestem 1-present
0-absent 17. Infrastaminalappendages
1-present 0-absent
5. Colletersatbaseofupperleafblade 1-present
surface 18. Corollatubesize
0-absent 0-minute(1-4mm)
1-present 1-small(6-10mm)
6. Colletersalongtheupperleafblade 2~medium(11 20mm)
surface 3-iarge(21-50mm)
O-absent 19. Filaments
1-present 0-minute(0-1mm)
7. LeaveswithdortTatia 1-medium(3 6rmm)andrunningalong
0-absent thestyle
1-present 2long(10mmandgreater)andseparate
8. Secondaryvenationofleaves fromthestyle
0-visible 20. Anthersfromribs
1-obsure 0-no
9. Tertiaryvenationofleaves 1-yes
0-visible 21. Stamenexposure
1-obsure 0-included
10. Calyxsize 1-anthertipsexserted
0-minute(0-3mm) 2-stamensfullyexserted
1-foliaceou5(5-15mm) 22. Antherswithapicalappendages
11. Calycinecolleters O-dbsent
0-absent 1-present
1-numerousandalternatewiththesepals 23. Antherdehiscence
2-solitaryandoppositethesepals 0-introrse
12. Aestivation 1-lalrorse
0-sinistrorse 24. Anthermorphology
1-dextrorse 0-Connectiveenlarged,thecadisplaced
2valvate laterally
13. Corollashape 1-Connectivenotenlarged,thecanot
O-salverform displaced,basesroundedandsterile
1-urceolate 2-Connectivenotenlarged,thecanot
2-infundibuli(orm displaced,basesforkedsterile
3-rotate 3-Connectivenotenlarged,thecanot
WILLIAMS,EVIDENCEFORANEWNEOTROPICALGENUSOFAPOCYNACEAE 121
displaced,basesrounded,anthersuni- flower,bothfusedonlyattheapicaltips
formlyfertile 2-Twofolliclesdevelopingfromone
25. Anther-styleheadrelationship flower,bothfusedthroughoutentire
0-anthersfreefromstylehead length
1-anthersfusedtostylehead 3-Onefollicledevelopingfromoneflower
26. Pistilhead 33. Foliiclesmoniliform
0-Pistilheadshort,pentagonal;f/ievef/a- 0-no
type 1-yes
1-Pistilheadelongatedpentagonal; 34. Folliclecolor
Mandevilla-iype 0-tan
2-Pistilheadfusiform;fc/i/fes-type 1-red
27. Nectary 2-black
0-absent 35. Fruittexture
1-5freenectaries 0-herbaceous
2-nectariesfusedintoacup,fc/i/res-type 1-woody
3-nectariesfusedintoacupThevetia-type 2-leathery
28. Inflorescenceposition 36. Seedswithcoma
0-axillary 0-absent
1-terminal 1-presentandsessile
29. nflorescencemorphology 2-pre5entandrostrate
0-raceme 37. Pollenapertures
1-corymbose 0-tricolporate
2-reducedcyme 1-triporate
30 nflorescencebranching 38. Exinepattern
0-absent O-smooth
1-present 1 microreticulate
31. Fruittype 39. Pollenshape
0-linearfollicle(2-15mmindiameter) 0-spherical
1-robustfollicle(30-60mmdiameter) 1-triangular
2-drupe 40. Pollendiameter
32. Follicleorientation 0-20-35pm
0-Twofolliclesdevelopingfromone 1-40-75^im
flower,bothspreading 2-75-110Mm
1-Twofolliclesdevelopingfromone
ineffect.Theoptionformaximumtreesstoredwassetat10,000.Taxawitfi
multi-statecharacterswererecognizedaspolymorphicforthosecharacters.
Charactersweretreatedasunorderedandofequalweight.Attheendofthe
analysisthestoredtreeswererooted,withboththeoutgroupandingroupdi-
rectedasmonophyletic.Astrictconsensus(Fig.1)andamajorityruleconsen-
sus(Fig.2)treeofthestoredtreeswereproduced.Bootstrapvalueswerecalcu-
latedusing1,000replicateswiththePAUPsettingsat:fullheuristicsearch,
startingtreesobtamedviastepwiseaddition,randomsearchsetforadditional
sequenceswith10replicates,branchescollapseifmaximumbranchlengthis
zero,includegroupscompatiblewith50%majority-ruleconsensus,includeonly
informativecharacters.Themajorityruletree(Fig.2)ispresentedalongwith
bootstrapvaluesnearorhigherthan50%.
122 BRIT.ORG/SIDA21(1)
Table2.Datamatrixofthe40informativecharactersusedinthephylogeneticanalysis"-'-'presented
inthisstudy.
Species Characternumberandcharacterstates
0000000091 11111111112 2222222223 3333333334
1234567890 1234567890 1234567890 1234567890
Adeniumobesum 0010000000 112b010200 0102120110 000001000?
Angadenlaberterii 0101000000 1121000200 0002122010 0100120001
Apocynumcannabinum 0300000000 0110010000 0002121111 0000010000
Cerberaodollam 0010000111 1000101201 0010203111 2—1201112
Echitesagglutinata 1100000010 2101000100 0002121011 0110020000
Echitestufbinata 1100000110 2101300110 0002121011 0110020000
Echitesturrigera 0100000000 2100000200 0001121010 0100120001
Echitesumbellate 0100000000 2100000200 0001122010 0000120001
Echiteswoodsoniana 1100000110 2101000100 0002121011 0110020000
Echitesyucatanensis 0100000000 2100000200 0001122010 0000120001
Fernaldiapandurata 0100000000 2120000200 0001121010 0100120001
Forsteroniaacouci 0100101000 1130000010 2001121111 0000110000
Forsteroniamyriantha 0100101001 1130000020 2001121111 0000110000
Forsteroniapeninsulam 0101001001 1130000020 2002121111 0000110000
Forsteroniaspicata 0100100001 1130000020 2001121111 0200110000
Laubertiacontorta 1100000000 0102310210 1002121010 0110010001
Mandevillaacutiloba 0101100000 1101000100 0003111000 0100010001
Mandevillafoliosa 0201100000 1101000100 0003111000 0110010001
Mandeviliahirsuto 0101110001 1121000200 0003111000 0110010002
Mandevillasubsagittata 0101110000 1101000200 0003111000 0110010002
Mesechitestnfida 0101100000 1101000200 0003111011 0110010001
Nenumoleander 0000000000 112bO10200 0102120110 0100010000
Odontadeniamacrantiia 0100000001 1121000200 0002121010 1300120001
Parsonsialatifolia 0101000000 3230000010 2002121111 0200110000
Parsonsiaheteropiiylla 1101000000 323aOOOOOO 0002121all 0200111000
Parsonsiapraeruptis 1001000110 3230000000 2002121all 0200110000
Parsonsiapurpurascens 1101000000 3231000000 0002121111 0200010000
Parsorisiastraminae 1101000000 3231000000 1002121all 020011000?
Pentalinonandneuxn 0101000000 1121000200 0102122010 0100120001
Prestoniaacutifolia 0101000000 2101210110 1002121011 0100110001
Prestoniamexicana 0101000001 2101310210 1002121011 1000110002
Prestoniatomentosa 0101000001 2101210210 1002121011 1000110001
Prestoniaportobellensis 0101000001 2102210210 1002121011 0100110002
Rhabdadeniabiflora 0100000001 0120000200 0001121020 0000110002
Strophanthuskombe 0100000000 1120010200 1002120111 000001000?
Telosiphoniabrachysiphon 0200100001 1120000300 0003111120 0100010001
Jhenardiachiapensis 1100000010 2130000010 2002121011 0210010000
Thenardiafloribundo 1100000010 2130000010 2002121011 0210010001
Jhoreaueapaneroii 0100000000 2110010010 0002121011 0??0?'10000
Thevetiaovata 0010000011 1021101201 0010203111 2—2201112
Thevetiaahouai 0010000111 1001101201 0010203111 2—1201112
Tintinnabulanamortonii 0101101001 1121000220 0103111011 0??0?10001
.
WILLIAMS,EVIDENCEFORANEWNEOTROPICALGENUSOFAPOCYNACEAE 123
Table2.(continued)
Species Characternumberandcharacterstates
0000000091 11111111112 2222222223 3333333334
1234567890 1234567890 1234567890 1234567890
Tintinnabulariagratissima 0101101001 1121000200 0003111011 0110?1000?
Tintinnabulariamullaraensis 0101101000 1121000220 1103111011 0??0?10001
Trachelospermumdifforme 0101000000 1100000100 0002121111 0000?10000
aCharacternumbersandcharacterstatescorrespondtothoseinTable1
bPolymorphiccharacterstatesarerepresentedbylettersasfollows:a=0,1;b=0,3;(withinthedata
matrixcharacterstatesforpolymorphiccharacterswereenteredas0/1etc.Lettersareusedhere
fortheconvenienceofaligningthetable).
RESULTS
Thedatamatrix(Table2)of45taxaand40charactersincludednocharacters
thatwereuninformative.Ofthe1800cellsinthematrix14(.77%)werescored
withaquestionmarkforunknowncharacterstates.Thedatamatrixincluded
sixcharacterscodedaspolymorphicconstituting.33%oftheentries.
Theheuristicsearchyieldedatotalof48equallyparsimonioustreesof159
stepsandaconsistencyindex(C.I.)of0.434andaretentionindex(R.l.)of.767.
Thelowconsistencyindexreflectsthehighlevelofhomoplasy(Kitchinget
al.l998)withinthecharactersselected.Thehighlevelofhomoplasyprobably
alsoaccountsforthelowerbootstrapvaluesinthebasalbranches(Fig.2),
therebyreducingstabilityinthebasalclades.Stabilityisseenintheterminal
branches,whichisreflectedbythehigherbootstrapvalues(Fig.2).Thedis-
crepancyinsupportforthebasalcladesversustheterminalcladesisaccept-
ableconsideringthatthemainfocusofthisstudywastotestthemonophylyof
generaintheApocynaceae,inparticularEchites.
Theingrouptaxaformedtwolargeclades.Thefirstlargeclade,CladeI,is
comprisedoftwoclades.Inthefirstofthese,theWrightieaecladeissisterto
twosubclades:oneisrepresentedsolelyApocynum(Apocyneae);theother,the
Prestoniasubclade,iscomprisedofthreesmallersubcladesofgenerafrom
Echiteae,inwhichthegenusThoreaueaissistertotheothertwo;oneoftheseis
asubcladecomposedofEchitessubgen.Pseudechitesandthetwospeciesof
Thenardia;theothersubcladeiscomposedofLaubertiaandPrestonia.Thesec-
ondgroupofcladesinCladeIiscomprisedofthegenusTrachelospermum,
whichissistertotwosubclades:theForsteroniasubclade,andtheParsonsia
subclade,whicharecomprisedsolelyofthesetwogenera,respectively,thefirst
ofwhichisinApocyneaeandthelatterinEchiteae.
InCladeII,Rhahdadeniaissistertotwoclades.Thefirst,theEchitesclade,
includesasubcladeofAngadeniaandPentalinon(Echiteae)andOdontadenia
124 BRIT.ORG/SIDA21(1)
-Adciiiimioht'sam
-\(rii(}iioleander wRiGimi-At:
-Sln>phanthn\konihe
-ApocxnumcannahiinDu IAPOCYSEAE
-fuhih'\iiiiiilmltiiihi
-/yitifcslurbimiUi
~Ech'noswaoiisonii/fui
~fhciiitri/iac{niipcn\i\
-I'fu-nardiaflorihutuUi
-ixnibertiacoiHorla ECnrVEAE
-Pnwfimiu(icuii/olid
-Pre\li)uianiexicuna
-I'rc^toiiiulo!tH'f)!osa
-Pffsioniaporloheilcnsis
Tlutrcaueapaneroii
-/-'irsWrfjftiaf>cnifiMihrri.\
-/orsivroniaspicaui APOCYSEAE
-I-Drsicroniamyriunlhn
~l-(irs!ev<iniaucouci
-i'tu-sons'uihaljiiliti
-f\ir\on\iapiirpurawciis
-riitKonsiahctcrt>phylUi ECUn'EAE
-Parsonslaslniimuae
-Parsonsiapraerupj^s
~Trachciv}>pennwndiffornic %APOCYSEAE
-AriiiodeninhrrtcriJ
-Pciihdiuonandr'iciixii
-I'Ahdc.sturrix^i'ia EOUTEAE
-At7//7t-'A-urnhvlluUi
-f-'i'nuiidh!pdiidurotd
-Odoniadeu'uiiiuknml/iti \APOCYSEAE
~Mandi'vdktuciitdoho
~KUuult'vdhifolioso
-\}<mde\'i}Uihlrsuui
-MandeviHasuhsa^ituthi
~Mcsechitestrifida MESECHITEAE
-luUiniuihiihtriiittmrtoHii
-Piiilhiiuihtflitriainurallacnsis
-flniinnahiiUiriai^rntissinin
-Tc((*\tpiunuabrutinsiphon
--CRfhrihdnclrdadoednfuliiahniifU'ra \EC11he:AE
-T/h'vdiu(du)H(U XPLUMERIEAE
-Thcvetiiio\uki
Fig.1.Strictconsensustree.TaxaincapitallettersandtotherightofthecladogramindicateTribesrecognizedinEn-
dress&Bruyns(2000).Note:Thoreauea(Williams,2002b)wasdescribedafterEndress&Bruyns(2000)andtherefore
notincludedintheirtreatment.However,Thoreouea,asdiscussedinWilliams(2002b),correspondstothedescription
oftheEchiteaeandisincludedinthistribe
WILLIAMS,EVIDENCEFORANEWNEOTROPICALGENUSOFAPOCYNACEAE 125
-Adi-iiiuiiiohesmn
75 -Neriiitnoleander
-18 ~SJritphaiuimsktmthe
-ApucvHitmcati/iahii/um
Eciiiti'sng^!urina!(i
NO Echiti'slurhimita suhf>PseiidechiieM
54 Echite.swoodsoniaiKi
-Thenardiach'uipciisi\
83 ThtfuardiaJIvnbiinda
Laidyvrtkiconlorta
Prc'\u>t]i(iiicuiifolia
46 Prcstaniamexicana
76 Pn'stofikiloineiifosti
54 Prcstoninporlnhvltcnsis
-Thorcaueupuneroii
-horsleroniapeni)}\uUiris
66 -Forsteroniaspkttla
61 -Forstcrnniamyrianiha
-Farstcroniuacouci
-ParMinskifaiifolia
-Parsonsiapurpurasccns
54 -Piirsunsitiheterophylici
51 -ParsonsiastramiiKiC
-Parsonsiapraeriiptis
-Tracliclospcrmumdijfornw
-Ans^ihli-niaberterii
76 -Pi'iit(dinouandrii'uxii
-Odoiuadeuiamacrautha
FcJii!c'\nirrigcra
Fchitcsyucataiieusis Mihi;.Echiles
76 Fcliiresumhelhui
~Fcriuddiapaiulurafa
~MatuU'viKaacuiilnha
-MondeIil/afuliosa
-Siandcviliahirsnio
64 -Maiidevillasubsagatiiui
~Miwcchilt'-SIrifida
50 74 --Tliltniitiinnnnaibditsditliarriiaamttouritnodnlio<i'n\is
70 -Tiffunnahidariai^raUssiiua
-Tcl('\if>hf'ntahrovliwipfutn
~RludHktdetuuhifkiro
-Ci'rhcroodvlhm
74 -ThevfOiiahotuii
-Thevi'tioova/a
Fig.2.Majorityruleconsensustreecalculatedfrom48mostparsimonioustrees(length165,CI=.434,Rl=.767,RC^
,333).Numbersbelowthebranchesarebootstrapvaluesnearorgreaterthan50%.
126 BRIT.ORG/SIDA21(1)
(Apocyneae),whichissistertoacladecomprisedofFerrtaldiaandEchites
subgen.Echites(allEchiteae).Thesecondmainclade,theMesechiteaeclade,
iscomposedofrepresentativesofMandeviUa,Mesechites,Tintinnahularia
andTelosiphonia.Comparingtheresultsobtainedheretothelatestclassifica-
tionof the family by Endressand Bruyns(2000),the Wrightieae and
Mesechiteaearesupportedasmonophyletic,whereasthe Apocyneaeand
Echiteaearepolyphyletic.
DISCUSSION
MonophylyofEchites.^TheresultspresentedhereindicatethatEchites,ascur-
rentlycircumscribed,isnotmonophyletic.Theplacementofsubg.Pseudechites
inacladebothdistantanddistinctfromsubg.EchitesrendersEchitespoly-
phyletic.Thisresultwasnotunexpected,sincethetaxaofsubg.Pseudechites
aremorphologicallydistinctfromsubg.Echitesinatleastthirteenobservable
characters(Table3;threevegetativeandf floralorreproductive).However,the
speciesthatfallwithintheoriginaldescriptionofsubg.Pseudechitesforma
wellsupported(bootstrap80%)monophyleticclade.
BecauseofthepolyphyleticnatureofEchitessensuWoodson,basedonthe
numberofdifferencesbetweensubg.Echitesandsubg.Pseudechites,andthe
stronglysupportedmonophyleticcladeofsubg.Pseudechites,itissuggested
thatthespeciesofsubg.Pseudechitesbetransferredtoagenusseparatefrom
EchitessensustrictoThenewgenusandappropriatenamecombinationsare
proposedinMorales&Williams(2004).
Phylogenyofsubg. Pseudechites.—Boththestrict(Fig.f)andthemajority
rule(Fig.2)treesshowsubg.PseudechitessistertoThenardia.Arelationship
betweenThenardiaandsubg.PseudechiteswassuggestedinWilliams(1998).
Thetaxashareincommonwaterysap,leaveswithinconspicuoussecondary
veins,andpollenofsimilarsize.Itshouldbenotedhowever,thatdespitethe
similaritiesinmorphologythebootstrapsupport forthecladecomprising
Thenardiaandsubg.Pseudechitesislow(37%).Nevertheless,basedonprevi-
ousobservations(Williams1998)andthedatapresentedhere,thehypothesized
relationshipbetweenThenardiaandsubg.Pseudechitesappearsrelatively
sound.
Monophylyandphylogenyofsubg.EcJiites.—Boththestrict(Fig.1)andthe
majorityrule(Fig.2)treesshowsubg.EchitessistertoEernaIdiaWoodson.There
isonlyonemajorcharacterdifferencebetweensubg.EchitesandFernaldi(a(sal-
verformvs.infundibuliformcorollas;Table3).Itwashypothesizedbeforethe
analysisthatEernaldiamightbranchwithE.turrigeraWoodson,duetotheir
similarfruittypes(folliclesfusedattheapex;character32:f)renderingsubg.
Echitesparaphyletic.Indeed,bootstrapsupport(Fig.2)is76%forthetwosubg.
E'chitfsspecieswithspreadingfollicles(E.umhe/lataandE.j/ucatanensis)while
supportforthebranchbasaltothesubg.Echitescladeisbelow50%.Regardless,