Aristidae Eludendae: Aristida hitchcockiana (Poaceae)-a valid species?

2005·2.1 MB·Latin

by  K W Allred

ARISTIDAEELUDENDAE:ARISTIDAHITCHCOCKIANA
(POACEAE)-AVALIDSPECIES?
KellyW.AIIred
RangeScienceHerbarium
DepartmentofAnimal&RangeSciences
NewMexicoStateUniversity
LasCruces,NewMexico88003,U.S.A.
[email protected]
ABSTRACT
Theoriginaldescriptionsandprologues,typespecimens,andavailablematerialolAristida
hitchcockianaHenrardandA.apprcsiciVaseywerecompared.Basedonmorphology,distribution,
andhabitat,thereseemstobenoreasontorecognizeA,hitchcockianaasavalidspecies,anditis
synonymizedwithinA.appressa.
RESUMEN
Secompararonlasdescripcionesyprotologosorigmales.ejemplarestipo,ydemasmaterialdisponible
deAristidahitchcockinaHenrardyA.apprcssaVasey.Basandoseenlamoriologia,ladistribucion
geografica,yelhabitat,parecenohaberindiciossuficientesparareconocercomoespecievalidaaA.
hitchcockiana.Porlotanto,selasinonimizaaA.apprcssa.
Aristidahitchcockianawasdescribedm1927byJ.T.Henrard,inhismonumen-
tal"ACriticalRevisionoftheGenusAristida'(Henrard1926,1927,1928).His
newspecieswasdescribedandillustratedashavinglongnarrowpanicles,sub-
equalglumes,thesecondtruncateoremarginate,andunequalawns(Fig.1).In
hisearlierworkontheNorthAmericanspeciesofAristida,A.S.Hitchcockin-
cludedthetype-to-beofA.hitchcockianawithinA.arizonica(Hitchcock1924).
Accordingly,Henrardcalledattentiontotheshorterspikeletsandawns,and
truncate,emarginateglumesofA.hitchcockianaascomparedtoA.arizonica.
Thenewspecieswasknownonlyfromtheoriginaldescriptionandfromthe
typecollectionatLasSedas,Oaxaca,Mexico(Hitchcock1935),andlargelyig-
noredornotrelevanttosubsequentworksonMexicanAristidauntilBeetles
LasGramineasdeMexico(Beetle1983),inwhichherecordedthespeciesfrom
sevenstatesinMexico.Idonotknowtowhichplantsheappliedthename,only
thattheillustrationisatvariancewithbothHenrard'sandBeetle'sownde-
scriptions,inthatitshowsan openpaniclewithspreadingbranchesand
pedicels,acuminateglumes,andlongcc(ualawns.Inthesepublicationsandin
Henrard'sprodigious"AMonographoftheGenusAristida"(Henrard1929,1932,
1933),A.hitchcockianawascomparedmostcloselytoA.arizonica,fromwhich
itwasdistinguishedbyhavinglongerglumes,lemmas,andawns,butwhich
belieditsmoreobvioussimilarities.
SIDA21(4):2n3-2118.2005
2114 BRIT.ORG/SIDA21(4)
Fig.1.Spikelet,2ndglumeapex,andcalluso^Aristidahitchcockiana[fromHenrard(1932)].
AcomparisonofAristidahUchcockiuuawithA.apprcssaVascy(Fig.2),
basedonoriginaldescriptions,typematerial,andspecimens,tailedtoreveal
anymorphologicalcharactersby which todistinguish them(Table1).For
1lenrard,thesinglemostdiagnosticteatureofA.hitchcockianawasthetrun-
cateandshortlyawnedapex(the"curioustip")ol thesecondglume,clearly
illustratedmtheorigmaldescriptionandrelieduponsolelyandexplicitlyin
thekeysofhisMonograph(Ftenrard1932,p.237).Thisfeatureisseenclearlyin
thetype,buteventhere,someol thesecondglumesareacutishandnotvery
truncate.Examinationofncady100specimensofA.appressashowedanearly
completegradationfromglumeswithtruncateandshortlyawnedapices,
throughaserieswithprogressivelylongerawnsandmorenarrowapices,tothe
otherextremeofglumeswithlongawns,acuminateapices,andnoticeablelat-
eralsetulae.Thetruncateapexcanbeeasilyoverlookedorobscuredwhenthe
glumeisfoldedorrolled.Perhapsthishasleadtothecharacterizationofthe
glumesofA.appressaasbeingacuteoracuminate(Henrard1932;Beetle1983),
ALLRED,ARISTIDAHITCHCOCKIANA—AVALIDSPECIES? 2115
Fig.2.SpikeletandcallusoiAristidaappresssa[fromHenrard(1932)].
wheninfactobtusetotruncateglumeapicesarefrequentlyencounteredin
thatspeciesaswell.Inaddition,Icouldfindnocorrelationofthiscondition(a
truncateapex)toanyotherfeature.Bothspeciesdeveloplongmternodes(longer
thanthesheaths),alineofhairsacrossthecollar(representedbyariminolder
material,orglabrate),noticeablylonghairsabovetheliguleontheuppersur-
faceoftheblade,andlateralawnsshorterthanthecentralawn.
Henrard(1929)calledparticularattentiontothe"verycuriouscrisppu-
bescence"oftheculms,paniclebranchlets,andlowerglumesofAristida
appressa.Thisiscausedbyascaberuloustypeofpubescence,usuallyinlines
alongtheridgesornervesoftheafore-namedparts.Itiswell-expressedinthe
typeofA.appressa,butmuchlesssoinmanyotherspecimens,andcancom-
monlybeabsent.ThissamescaberulouspubescenceisfoundinthetypeofA.
2116 BRIT.ORG/5IDA21(4)
Table1.ComparisonofAristidahitchcockianaandA.appressa.
Feature Aristidahitchcockiana,type Aristidaappressa
Culmheight(cm) 75 40 120
Pedunclelength(cm) 13 10-40
Internodepubescence glabrous glabroustopuberulent
Middlesheathlength(cm) 6-10 4-11
Sheathpubescence glabroustoscaberulous glabroustoscaberulous
Ligulelength(mm) 0.2 0.1-0.2
Auricleregion flaring,ciliolate,withhairs flaring,ciliolatetoglabrate,
to2.8mm oftenwithhairsto3mm
Collar scaberulousinaline glabroustoscaberulousina
line
Longestbladelength(cm) 17 14-30
Bladewidthwhenflat(mm) 1.8-2.0 1.5-2.5
Bladeinvolution flat,appearingtoberolled convolutewhenyoung,flat&
duetodrying curlingwhenmature
Blademargin slightlythickened slightlythickened
Bladeupperpubescence puberulent/scaberulouswith puberulent/scaberulouswith
scatteredlonghairsnearligule scatteredlonghairsnear
ligule
Paniclelength(cm) 17-24 14-30
Lowerbranchlength(cm) 4-6 5-12
Pulvin absent absent
Firstglumelength(mm) 8-10 5-12
Firstglumeapex acute truncatetoacuminate
Secondglumelength(mm) 9-11 6-12
Secondglumeapex truncatetoacute truncatetoacute
Glumepubescence scaberulousonthenerves glabroustoscaberulouson
thenerves
Lemmalengthtoawns(mm) 11-12 7-13(-16)
Lemmavestiture glabrousinthelowerpart, glabrousinthelowerpart,
scaberulousintheupper scaberulousinupper
Lemmabeak slightlyexceedingtheglumes egualtomuchexceedingthe
glumes
Calluslength(mm) 0.6-0.8 0.6-1
Centralawnlength(mm) 12-15 15-22
Lateralawnlength(mm) 6-9 7-17
hiichcoikiana.onculminternodcs,branchlcts,andthelowerglumes.Thisfea-
turehasthesamedegreeolinconsistencyasthetruncateglumeapex:ranging
Fromnoticeablypresenttoabsent.
hlenrard'sholotypecamefromLasSedas,Oaxaca,Mexico(approximately
100kmnorthwestofthecityofOaxacaonhighway131,atN17,.3523°W96.9444°),
collectedbyCharlesL.Smithsometimein1894.Thevillagewasaformerrail-
roadstation,andsitsatabout2100minapine-matorraltransitionzone,acom-
monelevationandhabitatforAristidaapprcssa.AnsLidaappressaisfoundin
ALLRED,ARISTIDAHITCHCOCKIANA—AVALIDSPECIES? 2117
allthesurroundingstates(Chiapas,Veracruz,Puebla,Guerrero),aswellasin
Oaxacaitself.
ThebasisforAristidahitchcockianaseemstobesimplyoneendofasingle
lineofvariation.Itsrecognitionispartlyanartifactofobservation:noticedina
fewplantswheretheglumesarenotfoldedorrolled,butoverlookedinother
plantswheretheglumeapicesareobscured.Itlacksanydistinctivemorphol-
ogy,distribution,orhabitat.Forthesereasons,thenameA.hitchcockiana
F-IenrardissubsumedwithoutrecognitionundertheoldernameA.appressa
Vasey,asdetailedbelow.
AristidaappressaVaseyContrU.S.Natl.Herb.1(8):282.1893.Type:MEXICO.Jaijsco:
Guadalajara,1886,E.Palmers.n.(ilOLOTYPE:US-745676!;LSOTYPHS:Lfragin.,W).
AristidahitchcockianaHenrard,Mcdcd,Rijks-Herb.LeidenNo,54A:233-234,1927.TvPll:
MEXICO,Oaxaca:LasSedas,1894,C/.,Smith918(holotype:US-991670!).
Selectedspecimensexamined(ol76total):COSTARICA.Guanacaste:4kmWoftheInter-Ameri-
canHwyontheroadtoMurcielago,320m,24Oct1968,R,Pohl11324(F),ELSALVADOR,Chalatenango:
alongHwy4,4kmSSEofLaPalma,pmcforest.950m.IfJunf970,R,Pohl11890(F).GUATEMALA.
Chimaltenagno:nearRioPixcayo,oakandpineforest,1650-f88m,3Feb1939,RStandJey64492(F),
Huchuctcnango:aboutLagunadeOcubiia,HofHuehuetenango,1900m,7Jan1941,RStandky82725
(F),HONDURAS,Comayagua:hall-wa)'betweenComayaguaandVillaSanAntonio,25Jan1936.W.
Archer3841(US),ElParaiso:grassypineforestofCuestaGalerasroadtoGuinope,1400m,24Nov
1970,A,MolinaR,25913(US),Morazan:openhillside,Sta,ClaraCreel,RioYeguaneValley800m,17
Dec1946,L,Williams11259(G);regionofLasMesas,steeppine-woodedslopes,800-900m,14Oct
1199501,inj,SthwealZliennac1a0n7t4a0n(UpSa)r,ajMeEXofICMuOc.taCjhoica,pa3s5:00stefte,p17roAcukygs1l9o6p5e,wD,itBhreQeudelrocveus11a8l6o9ng(F)M;ex11ickamnWHwoyf
TuxtlaGutierrezmrollinghills,24Oct1973,F,Gould14433(NMCR),DistritoEederal:VillaGuer-
rero,21Oct1960,T,Tateoka1139(US),Guerrero:Manchon,26Sep1936,G,Hinton9593(MO),
Guanajuato:about6kmeastofGuanajuato,rockysoilonanerodedhillside,17Oct1952,E.Sohns312
(CUrSu)z;kdemJ4v0e,nGtumaonaRjousaastorCuimtbyo-DaolGouraensajHuiadatlog,o,1S15epSe1p9811,94A6.,BEe.eHtleern7a3n59de(zMOX)o,loMceoxtizcio2:414,75k(UmS);WStoai,
TejupilcoonMexicanHwy134towardsTemascaltepec,1430m,6Oct1991,RPeterso?!11058(NMCR),
Oaxaca:LasSedas,in1894,Chas.LSmith9i8(US-type);4,8kmeolMitlaonMexicanHwy179to-
wardsAyutla,gentleslopesnearsmallcreekandcultivatedfields,1760in,14Sep1990,P.Peterson
9861(NMCR);NEofOaxaca,13kmNolElPuntoonMexicanHwy175and10,8kmSofGuelatao,
1970m,17Sep1990,RPeterson9936(NMCR);151kmSWofOaxacaonMexicanHwy190,oakwoods,
1100m,15Oct1976,J,Brunken369(MO);fromTemascalapatoSanlldefonsodeVillaAltaproper,on
openandrockymountainslopes.29-30Oct1944.J.VeraSantos3543(US);savannanearRevolucion
Mexicana,800m,3Nov1981,D,Breedlove54518(G),Puebla:nearCholula,aroundtheCholulapyra-
midandChurchNuestraSenoradelaRemedios,14Dec1972,A.Beetle2276(MO),Veracruz:3kmal
NdeChacalapa,400m,26Sep1965,J,Rzedowski21211(F),
ACKNOVv'LEDGMENTS
ManythankstothecuratorsofF,G,MO,US,andWIS,whokindlysupplied
materialforstudyandtoP,M.PetersonandS.L.Hatchfortheirhelpfulcom-
mentsasreviewers.DavidLeeAndersongenerouslyrenderedtheabstractin
Spanish.ThankstoJesusValdes-ReynaforadditionalinformationaboutLas
Sedas.
2118 BRIT.ORG/SIDA21(4)
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