Revision of Chionachninae (Gramineae: Andropogoneae)

36 Pages·2002·8 MB·English

by  Jannink, T A

BLUMEA 47 (2002)545-580
Revision of Chionachninae
(Gramineae: Andropogoneae)
T.A.Jannink & J.F. Veldkamp
Nationaal Herbarium Nederland,UniversiteitLeidenbranch,
P.O.Box 9514,2300 RALeiden,The Netherlands
Summary
Arevision is presentedofthe four genera ofthe SE AsianChionachninae Clayton (Gramineae:
Andropogoneae).Twelvespecies arerecognised:nine(withtwonewcombinations)inChionachne
R.Br.(incl. Sclerachne R.Br.) withanemendedcircumscription, oneinthereinstatedCyathorhachis
Nees exSteud.,oneinPolytoca R.Br.,and onein Trilobachne M.Schenck exHenrard.
Key words:Andropogoneae,Chionachne,Cyathorhachis,GramineaeP,olytoca,Trilobachne,Aus-
tralia, SEAsia.
Introduction
TheChionachninaeClayton(1981)are aSEAsianandAustraliansubtribeoftheAndro-
pogoneaeDumort.withfourgenera.Its twelvespecies arefairlyrare andhencehave
been treatedin some depthby only a few authors, e.g. Bennett& Brown inBrown
(1838), Henrard (1931,withadditionaltaxa addedin 1938and 1939),andby Nirodi
(1955).
Themostwidespread species oftheallianceisPolytoca digitata(L.f.) Druce,and
not surprisingly itwasthefirsttobedescribed.Linnef.(1782) regarded itas amember
ofApluda L., and calleditA. digitata.
Thenext one, Coix gigantea, was describedby Konig (1788) inarare publication
withavery vaguedescription andthenamewasnot enteredintotheIndexKewensis.
Thecombinationwasagain usedforCoixL. taxaby Jacquin (1820),Roxburgh (1814,
1832)andStapf(1896).ThelatterattributedittoKonig, but didnotcitethe 1788pub-
lication, and so he made alater heterotypic homonym. Roxburgh's application has
beenaccepted foraformofor aspecies relatedto Coixlacryma-jobiL. (Stapf(1896:
100)asavariety,reducedto var.ma-yuen(Rom.Caill.)Stapf(1897:421)). Bor(1960:
264) regarded it as a somewhat doubtfulspecies, which, when accepted, hastobe
called C. lingulata Hack. Itmaybeatetraploid form(Nirodi, 1955: 120).Isotypes in
BM, K,andUPS showthatKonig's nameactually referstowhatgenerally isknown
as Chionachnekoenigii (Spreng.) Thwaites,herethereforerenamedto Ch. gigantea
(J. Konig) Veldk.
Willdenow(1805-1806) describedCoixarundinaceaWilld., alater homonymof
Co.arundinaceaLam.(1791),anditwasthereforerenamedtoCo.koenigii by Sprengel
(1824), andsupposedly to Ch. barbataby Bennett(1838).
1) Correspondingauthor,e-mail: [email protected]
546 BLUMEA Vol. 47, No. 3, 2002
Contrarytolaterauthors(seethecausticremarkby Gould, 1994:111),Bennettdid
not makethecombination.Hestated "it mayperhaps beadvisable to substitute for
(CoixarundinaceaWilld.) barbata", andnot following his own advice did not
...
include itin his Index (see also Articles 34.1(a, b)). It was first madeby Aitchison
(1869) andagain by Bentham(1878)andDuthie(1883).
Unawareoftheexistenceoftheseearliernames, Roxburgh describedApluda digitata
L.f. again as CoixheteroclitaRoxb. andCo. gigantea as Co. barbataRoxb. (1814,
names only, validly published in 1832).
In 1838Brown distinguished thegeneraChionachneR.Br., Polytoca R.Br., and
SclerachneR.Br., whilein thesame chapter Bennett, apparently based on Brown's
notes,gave extensivecomments. They regarded thesegeneraas "apassage between
Coixand Tripsacum... tooevidenttobemistaken", immediatelypointing out,however,
theentirely differentorigins oftheinvolucreofthetwo. They also notedthecurious
prophyll intheCoix inflorescenceandremarked"no analogous organoccurs in any
oftherelatedgenera" (i.e.Chionachne,Polytoca, Sclerachne),whichisexactly another
reason why they are not closely relatedto Coix.Zea L., they wrote, is "manifestly
alliedtoPolytoca; andonewhosePaniceouscharacteris soobviousthatitis surprising
thatit shouldnot long agohaveassumeditsproperposition inthat tribe".
Bennettthoughttherewas nopedicelled spikelettothefemaleoneinCo. barbata,
butthere is a veryreducedone withits stipe completely adnateto thejoint. Healso
saidthatthemalespikelets wouldbesolitary; wehavealways seenthempaired, one
sessile,onepedicelled. ForPolytoca BennettremarkedthatRottboellia, i.e.R. cochin-
chinensis(Lour.) Clayton, is very similar, andthat"from Tripsacum to Rottboellia
thetransitionis easy". Phylogenetically it seemstobe theother wayaround.
Inthefollowing yearsseveralnewtaxa wereaddedandtransferredfromone genus
toanother,whiletwonew generawereadded:Cyathorhachis Steud.(1854)andTrilo-
bachneM. Schenck ex Henrard(1931). Henrard(1931), partly based onthe "notes
andsketches"madearound1912by "ProfessorDr.M.SchenckatSiegen",summarised
theworkdoneontheso-called 'Maydeae' Dumort.duringthe93 yearssinceBrown's
paper. This probably is MartinSchenck, aphysician inSiegen, "withaninterest in
grasses" (see Schenck, 1907;Mobius, 1927),fatherofJ.H.R.Schenck(see Stafleu&
Cowan, 1985:130-133). HenrardaddedChionachnehubbardiana(1938) andPolytoca
javanica (1939).Sincethennonewtaxa oftheChionachninaehave beendiscovered
andthediscussionatpresentis howthey shouldbe classified.
TAXONOMICPOSITION
Inmost accountsthegeneraareincludedinthe'Maydeae', atriberegarded asstanding
next tothe'true'Andropogoneae forwhichreasonitwas nottreatedby Hackel(1889).
Evenin recent accounts this positionis stillmaintained(Kellogg &Watson, 1993).
Actually, the 'Maydeae' is anomenclaturaland taxonomicmonstrosity. Nomen-
claturally, because 'Mays' Milleris not alegitimate name, andthere seems tobeno
correctnameforatribeincluding ZeamaysL.Taxonomically,becauseitisanartificial
assemblage of some generaof theAndropogoneae with monoeciousplants, with
unawned,unisexualspikelets indifferentpartsoftheinflorescenceorplant, withthe
T.A.Jannink & J.F.Veldkamp: Revision ofChionachninae 547
fruitsinsideaninduratedcoverofvariousorigin. IntheChionachninaeand Tripsacum
L.thecoveris formedby theinduratedlowerglume,inZeaby anumberofbracts(the
'husks'), inCoixby aninduratedspatheole.
Nirodi(1955)madeanextensive cytologicalanalysisoftheAsian'Maydeae' mainly
centredon varioustaxaofCoix, but shealso includedCh. gigantea (as Ch. koenigii)
andCh. macrophylla (Benth.) Clayton(as P. macrophylla Benth.). She concludedthat
ChionachneandPolytoca beara closeraffinityto eachotherthantoeither Coix and
theNewWorld 'Maydeae'.
The 'tribe' was definitivelybroken upby Clayton who distinguished atfirst two
(1973), laterthree (1981) apparently more 'natural'lines:
- Coicinae Rchb.fortheoriginally AsiangenusCoix, whichheregarded as derived
fromthetropical AsianApluda L. ofthe Ischaeminae J.Presl, where thefemale
inflorescencesarehiddeninastrongly induratedutricle, derivedfromaspatheole,
i.e.thetransformedsheathoftheuppermost leaf.
- Tripsacinae Dumort., restrictedtotheAmericangeneraTripsacum andZea,where
thefemalespikelets are solitary atthebase oftheinflorescenceandmoreorless
embeddedinto theinflorescence rhachis, and the male spikelets are terminalin
pairs ofasessileandapedicelled one(Tripsacum), or wherethe femaleinflores-
cences are axillary, thefemalespikelets aresolitary orpaired (Z. mays L.)andthe
maleone atthetopoftheplant (Zea).Thesubtribeis clearlyderivedfromtheRott-
boelliinae(J.Presl) Clayton (Clayton, 1973, 1981,andClayton &Renvoize, 1986:
"barely distinct").
- ChionachninaewithAsian andAustraliantaxa, wherethe sessilefemalespikelets
moreorless clasp theinflorescencerhachis(except inChionachnejavanica (Hen-
rard) Clayton) andare accompanied byamoreorlessreduced,atmostmalespikelet.
Themalespikelets wouldbe distalto thefemalespikelets, butCyathorhachis and
Polytoca havemalespikes atthebaseoftheterminalfemalespike, whichmayend
in eithersterilespikelets (Cyathorhachis) or maleones(Polytoca).
Especially theterminalinflorescenceofPolytoca has greatresemblancetothatfound
inRottboelliacochinchinensisanda derivationoftheChionachninaefromtheRott-
boelliinae,theso-called 'awnless Andropogoneae', seems probable(Clayton (1973);
Clayton &Renvoize(1986); seealsoBennett,as early as 1838!).Note,however, that
inRottboelliathelowerfloretofthesessile spikeletis male.
Clayton (1981) notedthatCh. javanica wouldhave"asomewhattenuous link to
Heteropholis" C.E. Hubb., now reduced to Mnesithea Kunth (see Veldkamp etal.,
1986),arottboellioidgenus,in whichthelowerfloretrangesfrom beingepaleate to
paleate, butsterile.
Thespecies first describedwereoften associatedwith Coixofwhichtheoriginal
concepthadbecomerathermuddled.Thebead-likeappearanceofthefemalespikelets
is not asharedcharacter:in Coixitis atransformedspatheole, intheChionachninae
itis the induratedlowerglumeofthe femalespikelet. Thefemalespikelet ofCoix is
solitaryandthemaleinflorescencesemergefromtheinvolucre.Theirrelativeposition
isdifficulttosee, asstructures areeasily damagedwhenattemptingto crackthebead.
They are on independent rhaches, themaleones situatedbelow the femalespikelet,
548 BLUMEA Vol. 47, No. 3, 2002
an arrangement foundin Cyathorhachis and Polytoca, too. In Coix, however, these
branches are separatedby aprophyll, aratherunexpected presencewhichsuggests an
originally lateralvegetativebranching system withintheutricle.WithintheRottboel-
liinaeprophyllsmayoccurin theinflorescence,but thenthey areassociatedwiththe
penultimate, not theultimatenode,seeforinstanceHemarthriaaltissima(Poir.)Stapf
& C.E. Hubb.as depicted by Vegetti (1993).
Cyathorhachis Steud.(1854) wascreatedfora verystrangespecies, Cy. wallichiana
Steud. from Bhutan, Sikkim, Bangladesh (Chittagong, Sylhet), Burma, and N and
SW Thailandfor whichareas there are few agrostological accounts: Stapf (Burma:
1896),Craib(Thailand: 1912),Bor (Burma: 1940, I960), Shukla(Mizoram: 1996),
Moulik(India: 1997)andNoltie(Bhutan: 2000). Also,ithasonlybeenrarely collected,
whichfactorsmay account forthefactthat,althoughithassomefeaturesthatexcludes
itfromthedefinitionoftheChionachninaeas given bye.g. Clayton &Renvoize(1986),
ithasbeenregarded asaspeciesofPolytoca. Ofallspecies here studied,itis, indeed,
mostsimilartoP. digitata, butsignificantly different,ascanbe seenfromthekey. Of
note arethefollowing features:
- Racemes digitateorpaniculate, withthemalespikeletsonlateralbranches,theter-
minalbranch 'mixed',i.e.atbase female, distallywithneuter,not well-developed
pairs ofspikelets. In P. digitata they are male. Note that Clayton (1981: 813; in
Clayton & Renvoize(1986); or. comm.to Esen & Hilu, 1993) describedthetribe
ashaving a"racemefemaleatbase,maleabovewithpaired spikelets" whichis not
the case here.
- Femalespikeletwithoutasecond floret,as was alsoobserved by Bor(1940). This
featureis mostexceptional forthePanicoideaeA.Br. as awhole. Theusualseries
inreduction withinthe essentially biflorousspikelet is from the base upward: in
principle thelowerfloretisbisexual(asinIsachne R.Br.sect.Isachne,andexcep-
tionally thecase intherestofthesubfamily), butis usually reducedtopaleate and
male, thenpaleate and sterile(often), to epaleate and so virtuallyabsent (e.g. in
Digitaria Haller).The position andnature ofthesinglefloret thenremaining can
be deducedfromthatoftheglumes, lemma,andpalea: theupperlemmais onthe
samesideastheupper glumeanditspalea onthesideofthelowerglume.
- Malespikelets with the apex ofthe lowerglumes long-attenuated, moreor less
awned,whichis unique inthealliance(but see some species ofVossiastraeStapf
(orVossiinae Pilg.) furthermentionedbelow).
These unique features, especially thedivisionofthesexes over thepanicle, are sug-
gesting thata distinct genus,ifnot asubtribe,is involved.
Polytoca digitatahasthe sametypeofinflorescence, butthefemalespikelet has the
'normal'complement offlorets: thelower sterileandepaleate, theupperfemale,and
the pedicelled spikelet ofthe male pair has an acute to somewhat attenuate lower
glume. Ifa distinctsubtribe is consideredforCyathorhachis, Polytoca shouldbein-
cludedin it. Otherwise, however,it appears tobeintermediatewiththeotherChion-
achninaeandthereforewehave refrainedfromrecognising one.
Nearly all species have at one time or the other been includedinPolytoca. We
regard thegenusas monotypic, and distinctespecially becauseof thestructureofthe
panicle.
T.A. Jannink & J.F.Veldkamp: Revision ofChionachninae 549
Trilobachnecookei(Stapf) M. Schenck ex Henrard is the most peculiar ofall and
onlyremotely similartoP. digitata.Ithas someunique features,e.g.thefemalespikelet
with a3-lobedlowerglume, a coriaceousupperglume, large fruits(4-5.5 mmlong)
with ahollowbase,and adorsalhilum.
SclerachnepunctataR.Br., ontheotherhand,hasnocharactersofsufficientimportance
to distinguish itgenerically fromChionachne.Thedifferencessuggested by thepro-
gramINTKEYusing theDELTAfilearebasedonerroneousobservationsorof specific
worth, e.g. sculpture ofthe lower glume ofthe femalespikelet, shapes, sizes, and
nervature ofthevariousparts, etc. Most similar, not necessarily most related, seem
Ch. hubbardianafromJava, Sumbawa,andAustralia, andCh. massieiBalansafrom
NandC Thailand,Laos,NVietnam, and? SChina(Hainan).Sclerachnepunctatais
thereforehereincludedinChionachne.The generic names are equallyold, butas the
lattergenusisrelatively betterknown,is thetypeofthesubtribe,andhasmostspecies,
itis tobe preferred.
MORPHOLOGY
The abbreviation'bbb',forbulbousbasedbristles, is usedforthosehairsthathavea
multi-cellularbase, visible as small pusticules when the usually setose hairs have
dropped off.
There is quite a considerablerange inculm length. Chionachnehas the smallest
plants, manynot reaching abovetheonemetre mark. In Ch. massieithereseemtobe
two types ofplants, onebeing tallandslender, theother smallandstocky.The cause
of thisis not clearandmay be duetoseasonal variation.
Chionachnemacrophylla iseasyto distinguish fromtheotherspecies by itsexcep-
tionally broad leaves (as itsname implies). Itisalso the only species inwhich only
someof the spikes are enveloped by aspatheole.
Only Ch. macrophylla andCh. javanica haveglabrous leaves.
Themargins atthesummitofthesheathnext tothe ligule(and usually adnatetoit)
mayform elongated appendages, the auricles.Theseare foundin Ch. javanica, Ch.
macrophylla, Cy. wallichiana, and P. digitata, and sometimes in Ch. gigantea and
Ch. massiei.
TheinflorescenceofChionachneiseitherasimple spike or acompound umbelof
severalspikes.Atthebaseofeachspike anumberofjoints havesessile, femalespike-
lets, accompanied by amuchreduced pedicelled one, distally thereare anumberof
joints withpaired male spikelets. This arrangementofaspike with both 'male'and
'female'joints is referred toin the key as a 'mixedspike'. This termhas also been
usedby Nirodi(1955: 108,key);fromherdrawing (t.4)wethinkthatshe meantthat
theterminalinflorescencewas maleandtheloweronesmixed.Wehavenot observed
such an instance,but itmaynot beruledout.
Assuming derivationofthistypeofinflorescencefromwhatispresentinRottboellia
cochinchinensisistempting: therethesimplespike whenwell developed has anumber
ofbisexualsessilespikelets inthelowerpart,then severalthataremale(!), whilethe
upperonesare muchreducedandsterile,as was alreadyobserved byBennett(1838!).
All pedicelled spikelets are sterile.Atfirst glancewhenone doesnot expect aChion-
achne species aspecimen mayeasily bemistakenforaRottboellia.
550 BLUMEA Vol. 47, No. 3, 2002
Trilobachnecookeihas anumberofmixedspikes inacompound umbel.Eachhas
1-3femalespikelets atbase with3-7pairs ofmalespikelets above.
Thesetwo generashowtheinflorescencestructurereported fortheChionachninae
by Clayton (1981),Clayton& Renvoize(1986), andConnor(1987), butCyathorhachis
and Polytoca are different:here there are both mixedand entirely malespikes. In
Cyathorhachis thebasalspikes havemalespikelets,theterminalonehasfemalespike-
lets atbase withneuterspikelets above.InPolytoca thelateralracemes also are male
(literaturesuggests that they mayhavebasalfemalespikelets aswell,butwe havenot
observed them), thecentralonemay havepairs ofmalespikelets belowanumberof
femaleones,abovethesethepairsofspikeletsare male,themost distalpairsofcourse
maybebadly developed andneuter.
Itis possible toassume thatinsomegeneratheinflorescencewithasinglespike is
derivedfromacompound one, andthatthelowerbranches havebeenlost.However,
such compound inflorescencesareabsentintheRottboelliastraeStapf(Jacques-Felix,
1962)or Rottboelliinae(Pilger, 1954),andapanicle wouldseemanautapomorphy.
Branchedpanicles arepresentinsome'Vossiastrae' (orVossiinae),insomeaccounts
implied to bethe sister groupofthe Rottboelliastrae(but see Kellogg & Birchler,
1993:f. 5).However,thepaniclesofPhacelurusGriseb.(sensu Clayton &Renvoize,
1986)andVossiaWall.& Griff, haveadifferentstructure.Curioustonoteis thepres-
enceofcaudateglumes insome ofthesespecies.
Itis thendifficultto deriveonestructure fromanother,but fairlyeasy to seethem
as havingtwo differentorigins inrottboellioidprogenitors. Theywouldthusrepresent
two differentlines originating inAsiaparallelled by theorigin oftheTripsacinae in
theAmericasandhencerepresenting a distinctsubtribe.
However,ifwedisregardtheinflorescencebranchingtheoverallsimilaritiessuggest
thatweare dealing withanatural, monophyletic group.
A good question, whichat present we are not prepared to answer, isofcourse,
whetherweshouldbecomesoexitedaboutunisexualspikelets atall, andreduce the
Chionachninaeto the Rottboelliinaealtogether. Watson & Dallwitz (DELTA grass
file, version3.14,1998)areabitambivalentaboutthis.Ontheonehandthey recognise
the 'Maydeae' as atribenext totheAndropogoneae, but atthesametimethey splitup
theAndropogoneae intotheawnedAndropogoninae J. Preslandthe unawnedRott-
boelliinaewhichincludesthe 'Maydeae' species again.
Reductionofsexuality is rampantintheAndropogoneae, bothwithinaspikelet, as
wellasbetweenspikelets ofonepair. Thepedicelled spikelets rangefrombisexualto
maleto steriletoabsent,rarely female(as inGermainiaBalansa& Poitr., wherethe
sessile spikelets are male).Soaseparation ofthesexes in aninflorescenceis not sur-
prising, culminating inaseparation ofsexes ontheplant as inZea. Monoecismhas
beenreported for62 grass genera,25ofwhichareinthePanicoideae(Connor, 1987)
andhasapolytopic origin.Itmay havebeenpolytopicfortheChionachninaeaswell.
The structure oftherhachis is thesamein all ofthegeneraandlike thatfoundin
the Rottboelliinae.Apparently the malepart falls offas awhole when distal,or is
long-persistent when presentbelowthe femalepart. Theaxis ofthefemalepart dis-
articulatesintofragments consisting ofasingleinternode('joint')towhichthefemale
spikeletandthepedicelled spikeletremainattached,as istheusualcaseintheRottboel-
T.A.Jannink & J.F.Veldkamp: Revision of Chionachninae 551
liinaealso.Ajointoccasionally mayhavethreespikelets, afeaturefoundinMnesithea
Kunth,formerly consideredtobeuniqueforMnesithealaevis(Retz.)Kunthandindeed
usual in well-developed spikes ofits var. laevis. In var. cochinchinensis(Lour.) de
Koning & Sosefandotherspecies of Mnesithea,however, itisofarare occurrence,
e.g.intheformerRatzeburgia pulcherrima Kunth(Veldkamp etal., 1986:289-290).
Triadsofspikelets arealso foundinLasiurusBoiss., andinthemoreremotely related
Polytrias Hack.
At maturity thebase ofeach jointhas a curious protrusion. It fits nicely into a
cavity atthetopofthejointbeneathitandissaidto containoilthatattractsantswhich
then carryoffthe diaspore. This structure has been called an 'elaiosome'.We have
notbeenabletodetectanyoilinthedried, usually veryoldspecimens, however.This
elaiosomeis derivedfromthevascularbundlesrunning throughtherhachis.Beumee
(1927) reported myrmecochory in Java for Ch. macrophylla (there cultivatedas
P. macrophylla), Ch. punctata (as S. punctata, also notedonMonoddeFroideville
1458), andP. digitata (as P. bracteata R.Br.), andtherottboellioidtaxa Mnesithea
glandulosa (Trin.) deKoning & Sosef(as Rottboelliaglandulosa), M. laevis (Retz.)
Kunth, M. mollicoma(Hance)A.Camus(as M.pubescens Ridl.), Ophiuros exaltatus
(L.) Kuntze, andR. cochinchinensis(as R. exaltataL.f.).Davidse(1984)becauseof
thepresenceofanoilyelaiosomesuspected myrmecochory forRhytachne gonzalezii
Davidse.
Thejointisratherinflated,andanotherdispersal mechanismmaybebyfloatingin
thesheetsofwater thatoccur aftertropical showers (Van derPijl,oralcomm.).
Atypical featureis thestructureofthefemalespikelets: Thelowerglumeofcourse
envelops theotherfloralpartsbutalsooftenpart orallofthejointas well.Thusthere
is the superficial resemblanceto the 'bead'ofCoix as mentionedabove. The apex
varies fromtruncate to three-lobed.Thebody assumes clearly distinctshapes which
are difficultto describein words.
The fruitoftheChionachninae,oncecarefully pried out from betweenthefloral
parts, is dorso-laterallyflattenedandconcave-convex. InTrilobachnecookeithebase
is hollow,intheothergeneraitis truncate toretuse.ThecharacterHenrardconsidered
tobethemostvaluableindistinguishingbetweengenera,namelytheshapeandposition
ofthe hilum, only partly shows the variationhe described. Nearly all taxa have a
basal, circular(to oval)hilum,only T. cookeidiffersby itslateral, (ovalto)linearone.
Therehavebeenonly afewanatomicalstudieswhichhaveincorporated species of
this subtribe. Of note are the summaries given by Watson & Dallwitz (1992: 220
(Chionachne), 736 (Polytoca, inch Cyathorhachis), 819 (Sclerachne)).
Afewchromosomecountshavebeenreported: Nirodi(1955) wasalreadymentioned
above.Thebasicnumberis 10,acommonnumberforthetribe.Chionachnepunctata,
Ch. semiteres(Benth. ex Stapf) Henrard, P. digitata, and T. cookeiare diploids, Ch.
gigantea(as Ch. koenigii) maybebothdiploidandtetraploid, whileCh. macrophylla
is tetraploid.
Thechromosomesareexceptionally large forthefamily, a characterthatis shared
withthe Rottboelliinaeand Tripsacinae (see alsoChristopher, 1986).
Membersofthesubtribeare occasionally includedinnumericalstudieswherethey
thenmayturnupinthemostremarkableplaces, puttingdoubttothemethodsemployed,
whenwe persist tomaintainthatitbelongs tothe Andropogoneae.
552 BLUMEA Vol. 47, No. 3, 2002
Hilu & Wright (1982) performed a numerical study on215 generabased on 85
morphological andmicroscopical datain whichChionachneclusteredwithMuhlen-
bergia Schreb.in theEragrostoideae Pilg.
Esen& Hilu(1993) studiedthedistributionofprolamin sizevariationandimmuno-
logical relationships inthePanicoideae.These supported themonophyletic origin of
thesubfamily anditstribes.They includedasingle collectionofCh. gigantea (as Ch.
koenigii), butnoneofthegenerawethinkareclose, asRottboelliaorZea. Remarkably
theyfoundit quitedistantfrompanicoid generaandinsteadassociatedwithDanthonia
DC., Digitaria, Eragrostis Wolf, andHordeumL. One suggestion offered was that
thiswouldreflecttheprimitivestatusofthesubtribeandthatoftheDigitariinaeButzin.
Thisis obviously unacceptable, asbothgeneraarevery derivedintheirown lines,and
atleastmorphologically havevery littleincommon.Anothersuggestion wasthatthis
resultwouldreflect thedistanceofChionachnefromthecore panicoid genera.The
error then isduetothesample beingtoo smallandanecdotalto detecttheactualrela-
tionships inasubfamily as large and diverseas this.Not beingfamiliarwiththe sub-
jectand methodology employed here,we disagree withtheresults, butcannot offer
analternativesolution.
Aphylogenetic study on amuch grander scale was madeby Kellogg & Birchler
(1993), moreextensively explained, butmoreor lessrepeated by Kellogg & Watson
(1993). Foritsmorphologicalandanatomicalanalyses usewasmadeofthevastDELTA
database with a matrixof220 morphological characters for94 generaofAndropo-
goneae.This supported theclassical idea ofthe 'Maydeae' being a single unitand
showedittobe distinctlyassociatedwithandnesting withintheRottboelliinaeclade.
Ifrecognised as a distincttaxon,theRottboelliinaebecomeparaphyletic (Kellogg &
Watson, 1993:299). Curioustonoteis thatinthefirstanalysis Chionachneteamedup
with Coix andthatPolytoca appeared tobe closerto Tripsacum than thelatteris to
Zea. This seems dueto the fact that the Rottboelliinaeclade is largely unresolved,
whichmay cause errors in higher branching.
Itmayalsobepointed out thattheDELTA databy necessity oftenhadtobebased
onaninterpretation ofexisting literature,e.g.thatofClayton & Renvoize(1986),and
inevitably containserrors, ase.g. withthe interpretation oftheinflorescencesofthe
Chionachninaeas notedabove. Kellogg & Birchler(p. 422) andKellogg & Watson
refined the analysis but in the firstpublication notedthat comparisons lack dataon
Chionachne,Polytoca, andothermembersof the Rottboelliinae.
Theirstrict consensus tree(Kellogg & Birchler, f.5) has a very low consistency
index(CI=0.25) possiblyduetothelargenumberoftaxa,whichaffects thecladogram
resolutionandmayexplain some curiouspositions, e.g.Polytrias as thesistergroup
oftheArundinelleaeStapf, whileits clearposition in theAndropogoneae closetoif
notidenticalwithEulaliaKunthisnot evidentatall.Also, GarnotiaBrongn.,generally
consideredaspartof theArundinelleaeas amonotypic subtribe, ratherunexpectedly
finds itselfin a quite heterogeneous clade with some Rottboelliinae, Chrysopogon
Trin.andVetiveriaBory, ImperataCirillo(but not MiscanthusAnderssonandothers),
etc.
T.A. Jannink & J.F.Veldkamp: Revision ofChionachninae 553
GEOGRAPHY
ThespeciesoftheChionachninaerangefromSriLankatoNPakistan,easttoSChina
andsouthtoNAustralia.Although forsometherangeiswide,theiroccurrence seems
tobe scatteredto disjunct and some are moreor less localendemics(see below).
In view ofthe known distributionofother species it seems unlikely that under-
collecting wouldbethe mainreason fortheapparentfragmentary distribution.Itis
morelikely due tochanges inclimatic conditionsover time,e.g. the desiccationof
CIndia,andthereturnofever-wet rainforestsinWMalesiawhereby suitablehabitats
wereobliterated.Thiswouldexplain theabsence ofany representatives in Sumatra,
PeninsularMalaysia, andBorneo, andtheoccurrence ofone species ofChionachne
inW Javaandthreeinthe dryeastern part.Asurvey:
ChionachnebiauritaHack.: endemic toLuzon.
Chionachnecyathopoda (F. Muell.)Benth.:restrictedtoN Australia.
Chionachnegigantea: SriLanka,NPakistan, Indiato Upper Burma,andthenagain
inN Vietnam(Ki-Luong).
Chionachnehubbardiana: N Australia, S Malesia (E Java andSumbawa), which is
typical fora drought species.
Chionachnejavanica: arare species ofareas with apronounced dry season: E Java
(Besuki, Puger), Flores,Alor.
Chionachnemacrophylla:Ternate(Moluccas), KaiIs., widespread inNewGuinea,to
theSolomonIslands.
Chionachne massiei: rare and local in N, C, and SW Thailand, Laos, N Vietnam
(Sontay), perhaps introducedin S China (Hainan).
Chionachnepunctata: a drought species of Java,Madura, the Kangean Is., andthen
inLuzon.
Chionachnesemiteres: scatteredinWand SIndia(Maharashtra: Osmanabad;Tamil
Nadu: S Arcot, Coimbatore,Tirunelveli) andthenagain in Burma(Mandalay).
Cyathorhachis wallichiana: Bhutan, Sikkim, Bangladesh, Burma, and N and SW
Thailand.
Polytoca digitata: Sikkim, NE IndiatoSChina,theninWtoEJava,afewlocalities
inthe Philippines, Celebes,andonceinPapua New Guinea(Northern Prov.).
Trilobachnecookei: WIndia.
CHIONACHNINEAE
Chionachninae Clayton (1981) 813. —Type: Chionachne R.Br.
Annualorperennial,monoecious.Auricles,whenpresent, usually adnatetotheshort,
scarious ligule. Inflorescences spatheate, consisting ofsolitary or digitateracemes.
Spikelets unisexual. Racemes eitherfemaleatbase, distally male(mixed), orbasal
racemes male,theterminalfemalemixed, i.e. distallywith maleor neuter spikelets.
Femalespikelet sessile, clasping the slenderjoint. Lodiculesusually absent(present
in at least Ch. gigantea, Ch. semiteres, and Cy. wallichiana). Fruit dorso-laterally
flattened, concave-convex, base truncate,retuse, or hollow. Hilumbasal or dorsal,
554 BLUMEA Vol. 47, No. 3, 2002
circulartooval. Pedicelledspikelet sterile, reducedtoalmostabsent.Malespikelets
paired, withtwo maleflorets, x = 10.
Distribution—Old Worldtropics, 4genera, 12species.
KEY TO THEGENERA
1a. Spikes digitate, lateralbranches male, terminalbranchmixed, atbase oftenwith
pairs ofneuter spikelets, then with a zoneof pairs ofonefemalesessileandone
neuterpedicelled spikelet, distallywithpairsofneuter ormalespikelets,thenoften
ending withpairs ofneuter spikelets. Femalespikelets: lowerglume not keeled.
—Femalespikelets: lowerglume withoutlateralappendages; upperglume partly
coriaceous.Fruitbase truncatetoretuse,hilumbasal. Sessilemalespikelets: first
paleakeeled 2
b. Spikelets arranged in solitary or paniculate mixed spikes. Spikes atbase with
pairs ofonefemalesessileandone neuterpedicelled spikelet, distallywithpairs
ofmalespikelets. Femalespikelets: lowerglumekeeled.—Femalespikelets: first
floretepaleate (paleate in Ch. javanica), second floretpresent. Malespikelets:
lowerglume muticous 3
2a. Pairs of spikelets above the female ones neuter, not well developed. Female
spikelets: firstfloretpaleate, secondfloretabsent.Maleandneuter spikelets: lower
glumeawned 2.Cyathorhachis
b. Pairsofspikelets abovethefemaleonesmale.Femalespikelets:firstfloretepaleate,
secondfloretpresent. Maleandneuter spikelets: lowerglume muticous
3.Polytoca
3a. Femalespikelets: lowerglumewithorwithoutlateralappendages, sometimeswith
anelongated toothon each side;upper glume herbaceousor partly coriaceous.
Fruitbase truncate toretuse,hilumbasal 1.Chionachne
b. Female spikelets: lowerglume apically winged; upperglume coriaceous. Fruit
base hollow, hilumdorsal 4.Trilobachne
1. CHIONACHNE
Chionachne R.Br, in Benn. & R.Br. (1838)15. —Type: Chionachne barbata (Roxb.) R.Br,ex
Aitch. (= Chionachne gigantea(J.Konig)Veldk.).
Sclerachne R.Br,in Benn.&R.Br. (1838)15, t.4.—Type:SclerachnepunctataR.Br.(= Chion-
achne punctata(R.Br.) Jannink).
Perennials.Spatheoles absentorpresentbeloweachpartial inflorescence, bladethen
well-developed toreduced. Spikes solitary or digitate, allmixed, distallywithpairs
of malespikelets.Femalepart: sessile spikelets embeddedinorenveloping thejoint.
Lowerglumemoreor less constrictedatorbelowthemiddle, keeled, apexextended
upwards ornot,withorwithoutlateralappendages, sometimeswithanelongated tooth
oneachside.Lowerglume marginsclasping, overlapping thejointornot;upperglume
herbaceoustopartly coriaceous.Firstfloretusuallyepaleate (paleatein Ch.javanica),
sterile.Fruit dorso-laterallyflattened,base truncate toretuse.Hilumbasal. Pedicelled
spikelets sterile, reduced toalmost absent. Malepart:sessile spikelets lowerglume
muticous.Firstpaleakeeledor notinthelowerpart. Pedicelledspikelets:lowerglume