Taxonomic status, ecology, and distribution of Carex hyalina (Cyperaceae)

7 Pages·1993·3.4 MB·English

by  A A Reznicek

Contr.Univ.MichiganHerb.19:141-147.1993.
TAXONOMICSTATUS,ECOLOGY,ANDDISTRIBUTIONOF
CAREXHYALINA(CYPERACEAE)
A.A.Reznicek
UniversityofMichiganHerbarium
NorthUniversityBuilding
AnnArbor,Michigan48109-1057
RobertF.C.Naczi
DepartmentofBiologicalSciences
NorthernKentuckyUniversity
HighlandHeights,Kentucky41099-0400
CarexhyalinaBoottisapoorlyunderstoodspeciesofthesoutheasternUnited
Statesinthedifficultandspecies-richsectionOvalesKunth. Itwasfirstdescribed
by Boott (1845) from a Drummond specimen collected along the Rio Brazos,
Texas,butwaslaterputbyBoott(1862)intothesynonymyofhisbroadlydefined
C. stramineaWilld. Mackenzie (1931)resurrected Carexhyalinaasaspeciesand
first distinguished it from the many other members ofsection Ovaleswithin its
range. Subsequently,essentiallyallauthorshaverecognizeditasagoodspecies.
MackenziereportedC.hyalinaonlyfromTexasandArkansas.Thefirstreportof
thespeciesfromOklahomaappearstobebyWaterfall(1960).Finally,Orzelland
Bridges (1987) summarized the distribution ofthe species up to that point, but
Carexhyalinaremainedanobscurespecieswithapoorlyknowndistribution.Our
aim is to remove this obscurity by clarifying the status of C. hyalina, including
typifyingthe name,providingacomprehensive description, anddistinguishingit
from other species in the section. In addition, we provide information on its
distinctiveecologyaswellasanup-to-datedistributionmap,supportedbyspeci-
mencitations,thatconsiderablyexpandstheknowndistributionofthespecies.
Carex hyalina Boott, Boston J. Nat. Hist. 5: 112. [7 Jan] 1845.—Type: Texas,
[?Rio Brazos, 1833,] Drummond s.n. "from Mr Borrer & Mr Christy.
1836." (holotype: K!; probable isotypes: Texas. Rio Brazos, Drummond
s.n.,1833,BM!,K-4sheets!).
Looselycolonialinsmallpatchesbyshort-creepingrhizomes,rhizomes0.5-7
mm long between shoots; fertile culms25-95 cm tall, trigonous, smooth except
just below inflorescence, where finely scabrous-angled; bladeless basal sheaths
pale brown, rapidly disintegratinginto short, darkbrown fibers. Leaves4-7, on
the lower 1/5-2/5 ofthe culm; blades ca. 3-20cmlong, 1-2.7 mmwide,plicate,
glabrous, the margins antrorsely scabrous; leafsheaths ca. 2 8 cm long, tightly
enveloping culms, glabrous, green; the inner band ofsheaths glabrous, whitish
hyaline, prolonged ca. 0.4-1.6 mm beyond the ± auriculatc leafbases, the apex
concave, whitish; ligulcs 2-3.5 mm long, rounded, the free portion entire to ±
erose, up to0.7 mm long. Vegetative culmsverydifferent fromthe fertile, fully
developedonlyaftertheperigyniaarelargelyshed,annualoroccasionallyover-
wintering,butneverbecomingfertile, 12-40cmtallwithca. 10-35leaves;leaves
tristichous and mostly clustered in the upper 1/4 ofthe culm, often larger than
141
142 CONTR.UNIVERSITYOFMICHIGANHERBARIUM VOLUME19
those ofthe fertileculms,ca.4-25 cmlongandupto3 mmwide. Inflorescences
1.3-4 cm long, the upper spikes usually overlapping, the lowest two spikes 2-9
mm distant; spikes single at nodes, sessile, lowermost bracts scalelike or some-
timeswithasetaceousawn,0.4-3.7cmlong,inconspicuous,sheathless,theupper
bractsmuch reduced;spikes2-4(-6),gynaecandrous;terminalspikesoftenslightly
largerthan the lateral,but otherwise essentiallysimilar, clavate-ovoid, 8-18 mm
long,pistillateportion6-12.5mmlong,6.5-12mmwide,ca.5-25 (-3())-flowered,
staminateportion 1-8(-11) mm long,0.7-1.2mmwide,ca.2-10-flowered. Pistil-
late scales 2.3 3.8 mm long, 0.8-1.6 mm wide, narrowly ovate, obtuse to acute,
silvery white to pale brown with a narrow green center, 1-nerved. Staminate
scales 2.4-4.5 (-5.2) mm long, 1.1-1.6 mm wide, lanceolate to narrowly ovate,
acute to acuminate, silvery white to pale brown with a narrow green center, 1-
nerved. Perigynia(4-)4.5-6.6mmlong,2.2-3.5mmwide, 1.6-2.4timesaslongas
wide,widelyspreadingat maturity,plano-convexto±biconvexwithellipticto±
suborbicularbodies(2.2-)2.8 4.7 mmlong,0.9-1.6timesaslongaswide,widest
1-2.4mmabovebase(0.2-0.4ofthetotalperigyniumlength),broadlywingedand
serrulate-margined except near base, + smooth or finely papillate, gradually
tapered into a beak, green to pale brown, glabrous, sessile, adaxial side 3-7-
nerved over achene, abaxial side 5-10-nerved over achene; beaks 1.4 2.8 mm
long,0.3-0.8timesaslongasthebody,stronglyflattenedandserrulate-margined
to apex, the apex bidenlate with scabrous-margined teeth ca. 0.1-0.4 mm long.
Achenes 1.8-2.6mm long,0.9-1.2mmwide, 1.7-2.4timesaslongaswide,bicon-
vex,narrowlyovate-oblong,palebrown,short-stipitate;stylestraightorveryslightly
contorted;stigmas2.Anthers3,ca.(1.1-) 1.3-2.6mmlong.
Spix'iMENsExAMiNiL). ARKANSAS. HcmpsteadCo.:nearFulton, 18Apr 1901,CunbyIS6aal.
(GH);Fulton,26Apr 1%5, Bush2459(MO).JacksonCo.:nearNewport,26Apr 1929, Palmer
35530(GH,MO);Hwy69attheBlackRiver,westofJacksonport,27Apr1989,Jones&Jones2531
(MICH.TAES);Jacksonport,JacksonportStatePark,neartheWhile River, 14May 1989,Naczi
217](MICH,UARK,ctb).LittleRiverCo.:2.7miSWofForemanalongSsideofrte.108,justEof
French Bayou,SE 1/4sec.29T12S R32W, 16May 1988,Naczi1913(MICH).MillerCo.:27Apr
1905, Bush2475 (GH, MO);Texarkana,28Apr 1905, Bush2500(MO). Pulaski Co.:May 1886,
Hasses.n. (KANU).St.FrancisCo.:LindenIslandsouthendofMadison.29May1960,McDaniel
(1c8t7b2);(2c.t5b)m.i—NMiWssisosfipLpuil.a,CoNahofomhawyCoU.S:24.95,Tm7iSNRW13oWf,Lsuelca.,1s2ecot.r1136..224MAapyr11997912,.MBrcyDsaonnw1l13185104&6
Newton (MICH, ctb). Tunica Co.: ca. 5 mi S ofTunica, 24Apr 1992, Bryson 11389 & Newton
o(fMITuCnHi,cac,tb2)4;Acap.r41m9i92S,EBroyfsTounni1c1a4,0284&ApNrew1t9o9n2,(BMrIyCsHon,1c1t3b9)6.—&OkNieawhtoomna.(MMIcCCHu,rtcatib)n;Ccoa..:171mmiiSS
2&W5a9t,1erE1f4aolMflaI1yd1a8b10e95l8,8(,1O5NKaALcpAzri,11T98E580X2.)(;WBa3Rt.eI6rTfm/ailSlMSU93o,2f5DjcU(t.RBRo.fIMTR/IRSCMHaU,n,dcOtrbtKe).L.A—2)5T9f;xia7ns.mIidBaSobewolif,eIadClaoob.ne:gl,cWa.181si0AdpemriofW19r5to4e,.f
Bassett,1.3miNofrte.259-1-30jet.,alongNsideSulphurRiverEofrte.259,IIMay1987,Naczi
1567(MICH).BrazoriaCo.:Columbia,31Mar1902,Bush1261(GH,MO).CassCo.:4.4miNEof
Naples,11 May1949,Cory55940(BRIT/SMU).DallasCo.:Dallas,Apr1876,Reverchons.n.(GFI);
Dallas, 1880, Reverchons.n. (BRIT/SMU,NY); Dallas,26Mar 1901, Reverchons.n. (GH, MO);
OWaksidCelifoff,T7riMnaityy1R9i0v1e,r,Re1v0eMrcahyon1928482,6N(aMczOi).18D5e9nt(oMnICCHo.,:TcAa.E5S,miTEEXo)f.DHeonutosnt:onSCoof.:rtea.lo3n8g0ratle.on7g,
onemileeastofTrinityRiver,11 Apr1964,Correll&Correll29125(BRIT/SMU,LL).LamarCo.:
sniedaeroPfartihse,RAipverr,19433M,aHyam19p7t2,onNis..xno.n(4U6S3)7.(LAiSbeTrCt)y;C0o..8:mJict.WofonHwHywy161205anfdrotmheitsTrjcitn.itwyitRhivtehre,ESasWt
NFMioarxdkoinsoof4n0t6Ch3oe.(:TAraSibnToiCtu)yt.R1Miovmerirr,iNs8WCMo.aa:nydalW1o9n8g9o,fEJtohseindeeisnot2fe7rr2so9euctt&eio2nW5io9pffjfuHswt{yAWS2T1oCf,atnhBdeRSITurTil/npiShtMuyrUR,iRvieMvreI,rC7Hbr,AipdTgrAeE1(S9j7)u2s.,t
N of1-30),5Jun 1989, Reznicek 8489(^ Naczi (MICH, TAES,TRTE,WARM,ctb). Polk Co.:
TrinityRiver,8.7miSonHwy59fromitsjctwithHwy190inLivingston.11May1988,Wipff830&
1993 REZNICEK&NACZI:CAREX 143
(fromFIlGivSi.ng1,pl2a.nPtervioguycnhieareadndbyinfRleozrneiscceeknc8es48o9f&CarNeacxzih)y.aliSncaal.e:Figb.ar1.=Pe1rimgmy.niaFigs.ho2.wiInngflloornegscbeenackess
showingperigyniaspreadinginthespikes(fromlivingplantvoucheredbyReznicek8489&Naczi).
Scale:bar=1cm.
Jones(MICH,PAUH,SAT,jkw,sdj).RedRiverCo.:ca.4miSEofJohntown:NofSulphurRiver
baoltontgomW,2s0idAe'prrte.1923781,,W1a1rnMeary2919(88C,M,NaTcEzXi)1;86S4am(MHIoCuHs,toTnENXa,tiUoAnaRlKF)o.resWta,lSkteurbbCloe.f:ieTlrdinLiatkyeR,iSveWr
ofHuntsville, 11 Apr 1992,Jones &Jones8243 (MICH,TAES).^WnnouT dkimnite LOCALrrv:
Herb.Boottexherb.Chapman(K).
Specimens considered isotypesvaryinthe completeness oftheirlabel data,
but all appear to be part of the same gathering, and it seems reasonable that
Drummondshouldhave found this uncommon species only once. The origin of
theChapmanspecimennotedbyBoott(1862)issomewhatofamystery,asCarex
hyalina apparently doesnot occur in the areaswhere Chapman did most ofhis
collecting. The specimen, however, lookssuspiciously similartothe Drummond
collections in aspect, stage ofmaturity, andpreparation, and perhaps Chapman
obtainedoneoftheseandfailedtorecordthedata.Allthreecollectionscitedfor
this species by Orzell and Bridges (1987) were seen, but not at NY or PH, the
herbariatheycited.
The affinities of Carex hyalina are somewhat uncertain. In spite of being
poorlyunderstood,itisactuallyaquitedistinctivespecieswithnoapparentclose
relatives.The keyinJonesandReznicek (1991)effectivelyseparatesitfrom all
the Texas species ofsection Ovales. Infact, the combination oflarge perigynia
[(4_) 4.5-6.6mm long, 2.2-3.5 mmwide], 3-7-nerved adaxially over the achene
withlong (1.4-2.8mm), somewhatpoorlydefinedbeaks (Fig. 1), andspreading
perigyniainfew-flowered [5-25 (-30)]spikes(Fig.2) isunique amongmembers
ofsectionOvalesinthesoutheasternUnitedStates.Thedistinctivehabit,colonial
by short-prolonged rhizomes producing numerous, well-developed vegetative
culms,aswellastheslender,few-spiked [2-4(-6)] fertileculmsallowC hyalina
to be readily recognized in the field. Correll and Johnson (1970) note that the
speciesthatmostresemblesC. hyalina,especiallywhenimmature,is C. brittoni-
anaL.FT.Bailey,alargerplantofopenhabitatsdistributedmostlytothewestand
southofthe range ofC. hyalina. Carexbrittonianashareswith C. hyalina large,
long-beaked perigyniaspreadingin relativelyfew,andsometimes few-flowered,
shpaiskelsonagnedrmaanydwmeullchbewtihdeerclposeersitgyrneilaati[v(e5.o5f-)C.6-h8y.a3linma.mHolownegv,e3r.,7-C6. bmrmittwoindiea]n,a
144 CONTR.UNIVERSITYOFMICHIGANHERBARIUM VOLUME19
FIG.3.DistributionofCarcxhyulina.
which are nervelessadaxiallyoverthe achene. VeryyoungspecimensofC hrit-
toniatuh without fully developed perigynia, can normally be separated from C.
hyalina by their longer anthers [(2.1-) 2.6-4.4 mm long] and longer staminate
scales(especiallyontheterminalspike,4.8-8.1 mmlong),whichusuallyhavethe
midrib excurrent as a distinct awn. Carex brittonicma also lacks the well-devel-
opedvegetativeculmsthataresuchaprominentfeatureofChyalina.
Boott(1862) and Mackenzie (1931)cite CarextetrastachyaScheele (1849)as
a later synonym of C. hyalina. Unfortunately, efforts to find the type ("prope
Neubraunfels leg. Romer") have been fruitless. Scheele's herbarium appears to
be lost, and few Romer specimens are known. New Braunfels, Texas (Comal
County), is at the east edge ofthe Edwards Plateau, well west ofthe presently
1993 REZNICEK&NACZI:CAREX 145
Tablf1.ResultsofanalysesofsoilsamplesfrompopulationsofCarexhyalina.
Locality pH Ca Fe K Mg P %org. % % % soil
ppm ppm ppni ppm ppm matter sand silt clay type
Arkansas:Little 7.7 7897 5 295 191 17 4.0 29.8 22.0 48.2 clay
RiverCo.,
Naczi1913
Mississippi: 7.0 4000 140 328 771 47 6.6 37.1 16.7 46.2 clay
CoahomaCo.,
Bryson11381
&Newton
Mississippi: 5.3 4000 139 480 922 55 5.4 17.1 14.7 68.2 clay
TunicaCo.,
Bryson11389
&Newton
Mis,sissippi: 5.4 3663 155 516 986 62 5.5 L5.1 18.7 66.2 clay
TunicaCo.,
Bryson11396
&Newton
Texas:Morris 7.0 6960 53 298 303 27 4.9 61.8 12.0 26.2 sandy
Co., Reznicek clay
8489&Naczi loam
Texas:RedRiver 7.5 8439 5 442 350 21 2.8 43.1 10.7 46.2 clay
Co., Naczi
1864
MEANVALUES 6.7 5827 83 393 587 38 4.9 34.0 15.8 50.2 clay
knownrangeofC.hyalina(Fig.3),whichcastssomedoubtonMackenzie'splace-
ment.Thelackofinformationabouttheperigyniainthedescriptionmayindicate
that the Romer specimen was probably quite immature; however, Scheele de-
scribedthescalesofC. tetrastachyaas"excurrentearistatae/'whichwouldapply
tothestaminatescalesofC. hrittoniana,aspeciesknownfromtheNewBraunfels
region,butnotatalltoC. hyalina.TheSchlottmannspecimen (LabadyPrairies,
Texas, K!) cited by Boott (1862) and sent to himby Sonder as an exemplar of
Scheele's C. tetrastachya is amixed collectionofC. brevior(Dewey) Mack, and
immature C. brittoniana. Mackenzie'sothersynonym, C. straminea "var.hyalina
Boott,"isnotvalidlypublished,sinceBoott(1862)merelycitedhisC. hyalinaas
"asmallvariety"underhisC.stramineavar.crawei,anddidnotmakethecombi-
nation at varietal rank. Efforts todetermine ifthis combination may have been
madebylaterauthorshavethusfarbeenunsuccessful.
Carexhyalinagrowsinshaded,wetsoiloffloodplainswoodedwithdeciduous
trees. SoilsofC. hyalinahabitatsshareseveralattributes(Table 1).Theconcen-
trations ofcalcium, potassium, magnesium, and phosphorous are high. In addi-
tion,theproportionofclayusuallyexceedsthesiltandsandfractions.Allbutone
ofthesoilsanalyzedpossessaclaycontentgreaterthan45% andareclassifiedas
clays.ThepHofthesesoilsareusuallynearlyneutral. CarexcorriigataFernaldis
a constant or nearly constant associate of C hyalina (Naczi & Bryson 1990).
OthervascularplantspeciesthatfrequentlygrowwithChyalinaincludeCblanda
Dewey, C bidbostylis Mack., C. cherokeensis Schwein., C cnis-corvi Kunze, C
socialisMohlcnbr.&Schwegman,andUlmiiscrassifoliaNult.
146 CONIR.UNIVERSnYOFMICHIGANHERBARIUM VOLUME19
Carex hyalina occurs in the west Gulf Coastal Plain and Mississippi Delta
physiographic provinces in northwestern Mississippi, eastern and southwestern
Arkansas, southeastern Oklahoma, and eastern Texas (Fig. 3). It grows in the
drainagesystemsofafewlargerivers:theArkansas,Brazos,Mississippi,Red,St.
Francis, Trinity, and White. Throughout its relatively small range, C. hyalina is
often abundant where found, but local, probably due to its specific habitat. It
should be sought on calcareous, alluvial clays elsewhere in the Southeast, espe-
cially in Louisiana, western Tennessee, and southeastern Missouri. The recent
successesoffieldbotanistsinlocatingnewpopulationsofC. hyalinaandexpanding
theknownrangeofthespecies(Naczi&Bryson 1990;Brysonetal. 1992)empha-
sizehowpoorlyknownC.hyalinahasbeenandmakethediscoveryofthespecies
in newregions quite likely. Onlyhalfadecade ago, C. hyalinawas known from
very few collections from a much smaller geographic range (Orzell & Bridges
1987). In fact, C. hyalinaiscurrentlybeingconsideredforadditiontotheUnited
States List ofEndangered and Threatened Plants (U.S. Fish & Wildlife Service
1990). Though C. hyalina is far from common, we believe its populations and
individuals to be sufficiently numerous and secure that legal protection of the
speciesundertheU.S.EndangeredSpeciesActisunwarranted.
ACKNOWLEDGMENTS
We thank the curators ofall the herbaria we visited or fromwhich we bor-
rowed specimens, especiallythose that sent us all their Ovalesso that we might
gleanafewsheetsofCarexhyalina:ASTC,BM,BRIT/SMU,CM,DUR,GH,K,
MICH, MO, NLU, NY, OKL, OKLA, PH, TEX/LL, UARK, US, ctb (C. T.
Brysonpersonalherbarium),sdj(S.D.Jonespersonalherbarium),andjkw(J. K.
Wipffpersonalherbarium).WearcespeciallygratefultoCharlesBrysonforsend-
ing us soil samples and specimens from his new discoveries in Mississippi and
StanleyJones forduplicatesofhiscollectionsinTexasand Arkansas.GaryLar-
sonkindlysentusinformationonspecimensofC.hyalinaonloantohim.
LITERATURECITED
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Bryson,C.T.,R.F.C.Naczi,andS.McDaniel.1992.Notesonnoteworthyrecords
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Correll, D.S.,andM. C.Johnson. 1970. Manualofthe VascularPlantsofTexas.
Renner,Texas:TexasResearchFoundation.
Jones,S.D.,andA.A.Reznicek. 1991.Carexhicknellii,''BicknelFssedge"(Cyper-
aceae):newtoTexas,withakeytoTexasspeciesofsection Ovales. Phytolo-
gia70: 115-118.
Mackenzie,K.K. 1931.Cyperaceae—Cariceae.N.Amer.Flora 18(1-3): 1-168.
Naczi,R.F.C,andC.T. Bryson. 1990.NoteworthyrecordsofCarex(Cyperace-
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Orzell,S. L., and E. L. Bridges. 1987. Furtheradditions and noteworthy collec-
tionsinthefloraofArkansas,withhistorical,ecological,andphytogeographi-
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Scheele,A.1849.BeitragezurFloravonTexas,Cyperaceae.Linnaea22:345-348.
UnitedStatesFishandWildlifeService. 1990. Endangered andthreatenedwild-
life and plants; review of plant taxa for Hsting as endangered or threatened
species.FederalRegister55:6183-6229.
Waterfall,U.T.1960.KeystotheFloraofOklahoma. Stillwater:OklahomaState
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