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