THE BLUE-EYED-GRASSES (SISYRINCHIUM: IRIDACEAE) OF ARKANSAS

8 Pages·1991·3.2 MB·English

by  Kathleen L Hornberger

THE BLUE-EYED-GRASSES
(SISYRINCHIUM: IRIDACEAE) OF ARKANSAS
KATHLEENL. HORNBERGER
DepartnimtofBiology, ScienceDivision
Widener Unii'ersity
Chester, PA 19013, U.S.A.
ABSrRAC;T
Dataobtainedfrommorphologicalcharactersandchromosomenumbermdicarethat
fsoelvieunmsMpielcli.e,soSi.Saitslyannntcihamn/n//Bsihcokunl.d,b.Ve.rceacnoilgwntirzeedBifcokrnA.r,kaSn.salsa:n^SU.mail!biGcrleumenReaf.{S,.S.praunigmmstntm-
Bickn.],S.nsulatnmBickn.\S.exileBickn.],andS.sagttuferiimBickn.Theseseventaxa
aredifferentfromtheeightpreviouslyrecognizedbySmithinthat.V,uipttijerumBickn.
Sw.asexinloetBliicsktned.,anwderSe.llainsgtleodisaisifGorueredniestainncdtSs.pperciiiesi.uouDiimstBriicbkunt.io,nplmuaspSs.wroesruelaptruomdBuiccekdn.usainndg
herbariumvoucherspecimens.
intr()i:>ik:tk)n
The genus Sisyrinchiim consists of both herbaceous perennials and
annuals with simple or branched stems that may or may not be con-
spicuously winged. The flowers are epigynous, subtended by a spathe
(made oftwo overlapping bracts), and have undifferentiated actinomor-
phic perianths. Themucronulatc toanstulate tcpals range incolorfrom
whiteoryellowwithpurplestripesandapurpleeye-ringtomoretypically
blue, purple, orwhitewith ayelloweye-ring.
No major revision had been done on this genus in the southeastern
United States since Small (1933), which did not include the state of
Arkansas. Smith(1978)recognizedeightspeciesforthestate:S. alhidum
Raf., S. angustifoltumMill., S. atlanticiim L^ickn., .V, campestreBickn., S.
exile Bickn., S. langloisu Greene, S. pruinosum Bickn., and S. rosulatuni
Bickn. Therefore, aspartofataxonomicrevisiononthisgenusintheSE
U.S. fortheSoutheasternFloraProject(Massey&Radford 1981), which
includesArkansas,specialattentionwaspaidtothisstate'sspeciesinorder
to update Smith'sAtlas(1978).
ThisstudywaspartofadissertationcompletedattheUniversityofArkansasinFayetteviUein
January 1987.
SiDA 14(4);597-6()'1. 1991.
598
systi-maik:study
A) Morphology
Several hundred herbarium specimens ofBlue-eyed-grass forthestare
wereexaminedfor24differentcharacters(Hornberger 1987a). Discrimi-
nantanalysisindicatedthatofthese24characters, thefollowingprovided
thebestseparationforArkansasspecies;pairedvs.singlespathes,lengthof
outertoinnersparhebracts(equaltosubequalvs. unequal), connationof
outerspathebract,stemwidth(includeswingoneithersideofraisedcen-
ter portion), stem wing width (average valueofboth wings), and dried
capsule color and shape. Flower color and shape arc also important
characters, butdonotpreservewell, andare, therefore, notreadilyavail-
able from herbariumspecimens. However, theyareincluded, alongwith
thecharactersmentionedabove, inthetaxonomickeywhichfollowsthis
section.
Essentially therearetwobasicmorphologicalgroups, onewithsimple
stems(.V. alhich/iuRaf.,.V.campestreBickn.,andS.sapttiferiimBickn.)and
onewith branched stems{S. angustijoliuniMill., .V. atlanttcmnBickn.,S.
IctnglmsiiGreene, andS. rosidatnwBickn.). Thespecieswithsimplestems
arearrangedinoneoftwoways: 1)thestemshaveeithersinglespathesona
scapethathasnocaulineleaf,hence, thereisnonodeor2)thestemshave
pairedsessilespathes(sometimesasingleone)subtendedbyacaulineleaf.
Thislattertypeofstemisconsideredtohaveonenode.Someofthesimple-
stemmedspeciesmay, however, occasionallybranch, particularly5. sagit-
t/JennN Bickn. (Hornberger 1987a). Species that typically have branched
stemshaveoneormorenodes, eachofwhichhasacaulineleafandoneor
more pedunculatespathes.
B) Chromosome Number
x=C8h,rowmitohsommoestreopfortthseinsptehceielsitbeeraitnugretientdriacpaltoeidtsha(tOltihveerge&nusLeiwsibsas1e9d6o2-n
Oliver 1966; Goldblatt 1982; and others).
Amongthesechromosomereportswerecountsofn=16fromflowerbud
materialforonlytwospeciescollectedinArkansas,S.campestnBickn.and
S. Liugloisii Greene (the latter taxon reported as S. pruinosnm, Oliver &
Lewis 1962;Lewis&Oliver1961).1wasabletoconfirmthisnumberfori\
camptstnBickn. from twodifferentArkansaspopulations,oneinHotSpr-
ing Co. and theother in Washington Co. (Hornberger 1987a).
Ialsoobtainedthecountofn= 16fromflowerbudmaterialforS.langlo-
isiiGreene,S. rosidatiimBickn., andS. sagittifernm Bickn., allcollected,
however, in Louisiana(Hornberger 1987a, b).
599
Sisyrinchii/m alhidum Raf. was reported as n=l6 from Louisiana by
Oliver&Lewis(1962). This numberwasoriginallyreportedbyBowden
(1945)forapopulationcollectedinVirginia. Itwasfurthersupportedby
Ingram(1964)forapopulationinTennessee. EventhoughIhavenothad
theopportunitytocountthenumberforthisspecies,itappearstobeoneof
the tetraploid blue-eyed-grasses.
Sisyrinchiinn angmtifolium Mill, has been reported as n=48 from
Louisiana by Oliver & Lewis (1962); they also reported this numberfor
several populations inTexas. Ihaveseen thesespecimensand agreewith
theiridentification. Hill(1984)recordedthissamenumberforaVirginia
population. However, Ingram (1964, 1967) reported n=40, 44, 45 for
populationsinNorthCarolina,Tennessee,andVirginia.Goldblatt(1982)
feelsthattheseconflictingreportsforthesamespeciesareprobablymorea
reflection ofmisidentification or incorrectcounts thancytological diver-
sity.
Sisyrinchuimatlanticum Bickn. has more reported diversity inchromo-
somenumberthantheprecedingtaxon.Numbersrangefromn=8(Oliver
1966)ton=16(Ingram 1964;Oliver 1966;Hill 1984)ton=48(Oliver
&Lewis 1962). IhaveseenthespecimenscollectedbyOliver(1966)andI
agreewiththeidentifications. However, 1haveseen theherbariumspeci-
men(Oliver253,ASTC)ofoneofthetwopopulationscollectedbyOliver
&Lewis(1962)fromTexasthatwasidentifiedas5^.atlanticumBickn.;this
specimenrepresentsS.biformeBickn.,aspeciesseeminglyrestrictedtothe
GulfCoast andoffshore islands.
C) Synonymy
ThegenusSnyrtnchiumhasbeenmisunderstocxltaxonomicallyformore
thanacentury. Becauseofsubtledifferencesinmorphology,disagreements
among botanists on recognition of legitimate taxa, synonymy, or the
properepithetforataxonhaveledtoaplethoraofspecies'descriptionsin
theliterature.Nomenclaturalconsiderations,then,becameamajortaskof
theSEU.S. revision. Holotypeswererequestedforalltaxa,andwhenthey
were determined lost or nonexistent, neotypes and lectotypes were
designated. TheonlytypespecimennotseenwastheoneforS. rosulatum
Bickn. becauseitwasunavailableforthisstudy. Acompletediscussionof
types and synonyms is included in Hornberger (1987a). Synonyms will
only be listed in this paper ifthey are different from Smith (1978) and
would causeconfusion if not included.
KT.YTOTUF.SFr,<:.Ii:S IN ARKANSAS
A. Outerspathcbratt norconnateatbase, oronlyslightlyso(1.0mmor
less) fi
600
B. Spachespairedattopofstem;bractsofouterspatheslightlyunequal;
sremwithasinglecaulincleafsubtendingthespathes .V.alhulumRaf.
B. Spathe single at top of stem; bracts unequal with outer one
I 1/2-")X lengthofinnerone;stemwithnocaulineleafsubtending
A. OCute•^S'rip^'astsppha'eitth-behreabcrtascteqcuoanlnattoesautbebqausael(1.1 mmormore) V camOCpestrcBickn.
DD..OOH.uuttSeetrressmppsaatt2hh.ee5bbmrraamccttoccroonnmnnoaartteeewaattidbbeaa,sseewifunoprgstmoo0r.2e9.0tmhmmamno2r..0m.om.r.emS.wi.sdu.ge.ii.St.liiferumBickn.
angiiUifoltiiniMill.
E. Stemslessthan 2.") mm wide, wingsless than0.9mmwide
F
F. Capsulespalebeigewithpurpleorbrownsutures,globoseto
subglobose; tepalswhiteoryellowwithjxirplestripesand
F. Cpuarpis:>ulleeesyeb-rrionwgn;ftolowbelrascku,rcgeloolbatoese.to..o.bSo.vartoeu;datteipaanlsBilcikgnh.t
blue to purple, sometimes white, with yellow eye-ring;
flowersrotate q
G.Innerspathe bract distinctly mucronate; spathes often
deflectedatbase;capsulesoblong-subglobosetoobovate
G. Innerspathebractnotmucronate;spathesnotdeflSe.ctaeildciantticKDiBickn.
base;capsulessubglobose S. langkisiiGreene
C. Spathebractsnoticeablyunequal H
H.Outerbractconnateatbaseupto2.0mm;outerbractupto3X
lengthofinnerbract S.uigittijennnBickn.
H.O1u/2te—r2brXactlecnogntnhatoefiatnnbearsebrmacotrethan2.0mm;outerbractonly 1
J. Stems2.0mmormorewide,wings0.9mmormorewide;tepalsJ
lightbluetowhitewithyelloweye-ring;flowersrotate;capsules
J. Sdatrekmsbrleoswsnthan2.0mmwide, wingslessthan0.9m9mcwni^dmtei;foluimMill.
tepalswhiteoryellowwithpurplestripesandpurpleeye-ring;
flowersurceolate;capsulespalebeigewithpurpleorbrownsu-
'^'-"'^^ S. roiiilatiimBickn.
DISCUSSION
Sevenspecieswererecognizedinthisstudyandwillbebrieflydiscussed
in alphabetical order.
SisyrinchiumalbidumRaf.isasimple-stemmedperennialwithpaired
sessilespathesatthenode,wherealargecaulincleafisfound. Flowersare
usuallywhitewithyelloweye-ringsandtheglobosecapsulesdrypalebeige
toastrawcolor. Populationsbloom lateMarch toAprilandarefoundin
prairies, woods, and roadsides.
SisyrinchiumangustifoliumMill, isthemostcommonand mostro-
bust species ofBlue-eyed-grass in the state, with fairly wide leaves and
601
stemswithconspicuouswings.Thisperennialproducesstemsthattypical-
lyhave 1nodewithacaulineleafwheretwopedunclesemerge.Flowersare
light blue in color with yellow eye-ringsand theglobose tosubglobose
capsulesdrydarkbrown.Plantsarefoundinfields,woods,oralongroadsi-
desinAprilandMay. Thistaxonhasaveryconfusingnomenclaturalhis-
tory which is presented elsewhere (Hornberger 1987a), but several
manualscurrentlyinusehavenamesconsideredsynonyms:S.bermudtanum
L. emend. Fern, and S. graminoides Bickn. (Gleason &Cronquist 1963;
Steyermark 1963)-
Sisryinchium atlanticum Bickn. is a branched species found in
swciatthter1e-d2praniordieesa,reaansdinartehenasrtratoew.lyStweimnsgearde(te1retmemtowsildieg)h.tlySpfaltahtetseneadr,c
small, often deflected at the base; bracts are equal to subequal, and the
inner bract is distinctly mucronate. The oblong-subglobose to obovate
capsulesdry darkbrown to black. Flowersaregenerally light bluewith
yelloweye-rings, butthetepalsaresometimesdarkbluetopurple. This
perennial taxon blooms from March to April.
Sisyrinchium campestre Bickn. is commonly found in prairies,
meadows, andgrassyareasalongroadsidesinAprilandMay. Thisperen-
nial has asimple stem with asingle spatheat the topofthescape. The
bractsofthespatheareverynoticeablyunequal,withtheouteroneatleast
1-1/2 to 2 timesormore the lengthofthe inner, gibbousone.
Sisyrinchium langloisii Greene is a branched perennial found along
grassy roadsides, prairies, and disturbed areas in March and April. Its
spathebractstypicallyhaveapurplecolorationwhichisoftenrestrictedto
thebaseofthespathe.ThistaxonissimilarmmorphologytoS.pnnnomm
pBriecskenn.t,ianltthhoeulgahttetrh.eBpoutrhplreaxcaolhoarvaetiotnheofsatmheescpharthoemobrsaocmtesinsugmebneerra,ll2ynno=t
32(Lewis&Oliver 1961;Oliver&Lewis 1962),andhavebeenreportedto
hybridize in areas of overlapping range (Correll & Johnston 1970).
ComparisonofflavonoidspotprofilesbetweenapopulationfromTexasand
another from Louisiana showed similar patterns (Hornberger 1987a).
Morphology, chromosome number, and flavonoid chemistrysuggestthat
these various populations mayactually be variationsofonelargespecies
complex; therefore, I have synonymized S. pniinosum Bickn. under the
oldername, S. langUnmGreene.
Sisyrinchium rosulatum Bickn. is the only annual Blue-eyed-grass
foundinArkansas,seeminglyrestrictedtoseveralsoutherncounties,plus
PolkCounty. Flowersare yellow towhitewith purpleto maroonstripes
and purple to maroon eye-rings. These flowers are urceolate, instead of
rotateasdisplayedbytheflowersoftheothersixtaxa. Spathesareslender
602
a1n-d1f/o2liatciemoeLiss,lownigtehrtthheanouttheerinbrnaecrtbrsahcgth.tlGylofbaolcsaetetoatsutbheglaopbeoxseancdapsouflteesn
drypalebeigewithpurpletobrownstripesalongthesutures. Populations
can be found in disturbed areas ofroadsides and lawns, prairies, river
bottoms,andpinewoods.Synonymsincluded.ex/^Bickn.(Smith 1978).
Sisyrinchium sagittiferum Bickn. is represented only from Miller
County,withpossiblehybrids{sagittiferum X Uinglonii)collectedinUnion
County. Thistaxon is usuallyrepresented bysimple, leaflessstemsoften
withfibrousbases.Spathesaresingle(orsometimespaired)atthetopofthe
scapes, being conspicuously broader than the stems. Spathe bracts are
equal or the outer one can be three times the length ofthe inner one.
Flowersarebluetopurplewithyelloweye-rings,bloominMarchtoApril,
andproducedarkbrown,globosetosubglobosecapsules,oftenwithsub-
marginal veins.
ThislattertaxonismostsimilarinmorphologytoS. campestreBickn.,
butdiffersinseveralimportantrespects: I)^.sagittiferumhasouterspathe
bractsthatareconnateforseveralmm;S. campestrehasnon-connateouter
bracts(less than 1.0 mm); 2)spathesof^. sagittiferumareconspicuously
wider than the stems and dry brownish, often mixed with purple; S.
campestrehasbractsthatdrygreenincolorandarenotconspicuouslywider
thanthestems;and3)S.sagittiferumoftenhasfibrousleafbasesattachedto
the stems, S. campestreseldom does. Sisyrimhiumsagittiferum Bickn. had
MbeyenstruedcyordienddicfaorteAsrkthaantsaistsbhyoDuledmabreeeco(n1s9i4d3e)r,edbuptarntotofbAyrkSamnistahs'(1f9lo7r8a)..
SUMMARY
Basedondatacollected in thisstudy fromobservation, investigation,
and literature review, sevenspecieso{Sisyruichiumare recognizedforthe
state ofArkansas: S. alhidum Raf., S. angustifolium Mill., S. atlanticum
Bickn.,^. campestreBickn.,S. langloisiiGreene,S. rosulatumBickn., and
S.sagittiferumBickn. ThisinformationispresentedinSmith(1988). Dis-
tributionmapswerepreparedforeachtaxonbasedonherbariumvoucher
specimens. Adotindicatesthatatleastonespecimenexistsforaparticular
taxoninaparticularcounty(Fig. 1).(Note:thedotinUnionCountyfor.V.
sagittiferumBickn. representspossiblehybridsbetween itandS. langloisii
Greene).
a(:knowli;dc;i:mi;nts
IthankE. B. Smithforservingasmydissertationadvisor.Manythanks
toJerryShellandhiswonderfuldog,Mittens,forhelpingmecollectflower
buds. I would also like to thank the Arkansas Native PlantSociety for
^
603
g. albidumRaf
—
S. campestre Bickn. p. lanaloisil Greene
S. rosulatuinBickn. g. flaaitt-iferumBickn.
FIG 1.DocumenteddistributionofArkansasSnyrinihiiim.
awardingmetheAileenMcWiUiamsScholarshipinBotanyin 1986which
provided encouragementand financial support to finish mydissertation.
Specialthanksarealsoextendedtothecuratorsofthefollowingherbariafor
lending mespecimens that madethis studypossible: ASTC, BH, BLH,
BM, FLAS, FSU, GA, GH, LAP, MA, MIN, MO, NCSC, NCU, ND,
NDG, NLU, NY, PH, SMU, TENN, UAM, UARK, US, andWIS.
604
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DEMTeAxRasEER,eseaDr.ch1F9o4u3n.datAionc,ataRleongnueer.of188th1eppv.asc(uSliasyrrmpclhainimtis,opfp.Ar4k2a5n-sa4s2.8)T.axod.um
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