The taxonomy and preliminary conservation status of Eriogonum shockleyi S. Wats. in Idaho

90 Pages·1996·14.3 MB·English

by  Moseley, Robert K

BUMLIBRARY
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88044239
The Taxonomy and Preliminary
Conservation Status ofEriogonum
Shockleyi S. Wats, in Idaho
by
RobertK.Moseley
and
JamesL.Reveal
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TECHNICALBULLETINNO.964 IDAHOBUREAUOFLANDMANAGEMENT February1996
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THETAXONOMYANDPRELIMINARYCONSERVATIONSTATUSOF
ERIOGONUMSHOCKLEYIS.WATS.INIDAHO
by
RobertK.Moseley
ConservationDataCenter
IdahoDepartmentofFishandGame
600S.Walnut,P.O.Box25
Boise,ID83712
and
JamesL.Reveal
DepartmentofBotany ^
UniversityofMaryland
CollegePark,MD20742-5815
November1995
m
LowerSnakeRiverDistrict,BLM
IdahoDepartmentofFishandGame
PurchaseOrderNo.D010-P5-0063
ABSTRACT
EriogonumshockleyiS.Wats,isararespeciesinIdaho,beingdisjunctfromthemainportionofits
distributionintheGreatBasin. Twovarietieshavebeenrecognizedinthestate,theendemicvar.
packardae(Packard'sbuckwheat)andthetypicalvar.shockleyi(Shockiey'sbuckwheat). Sincethe
endemicvarietywasfirstrecognizedinthemid-1970's,therehasbeenconsiderableconfusionasto
theidentityofpopulationsinthestate. Thishashinderedconservationplanningforthetwotaxa.
Our studyobjectivesweretoconductataxonomicassessmentofEriogonumshockleyiinIdahotoaid
inidentificationandmakeapreliminaryassessmentofitsconservationstatusinthestate.
TaxonomicanalysisrevealedthattwoentitiesdoexistinIdaho. Weprepareddescriptionsfor£.
shockleyianditsvarietiesinIdahoandconstructedakeytoaidinidentifyingpopulations. Wealso
discussthebiogeographicsignificanceoftheIdahopopulationsofE.shockleyiinthecontextof
conservationplanning. Emphasiswasplacedondetenriiningthetaxonomicstatus,butweused
existingdatatomakepreliminaryassessmentsoftheconservationstatusofthetwovarieties.
Packard'sbuckwheatisknownfrom11extantpopulationsandisgloballyrare. Populationsare
small,localizedandsomearethreatened. Itdeservesrecognitionatthefederallevelasacandidate
taxon. Shockiey'sbuckwheatisgloballycommonandsecure,butrarewithinIdaho. Itisalsoknown
from11populations,butingeneraltheytendtobelargerthanPackard'sbuckwheatandthreeoccur
instateparksoranationalmonument,wheretheyarerelativelywellprotected. Thorough
rangewide/statewidefieldsurveysareneededtodeterminethefullextentoftheirdistributionsand
abundanceinIdahoandtheirtrueconservationstatus.
TABLEOFCONTENTS
ABSTRACT i
TABLEOFCONTENTS ii
LISTOFAPPENDICES ii
PREFACE 1
SECTION1 -TAXONOMY 2
SECTION2-CONSERVATIONSTATUS 14
ERIOGONUMSHOCKLEYIVAR.PACKARDAE 15
ERIOGONUMSHOCKLEYIVAR.SHOCKLEYI .22
REFERENCES 23
LISTOFAPPENDICES
Appendix1. Morphometricdatafrom19EriogonumshockleyicollectionsmadebyBobMoseley
during1995.
Appendix2. OccurrenceRecordsforEriogonumshockleyivar.packardaefromtheConservation
DataCenterdatabase.
Appendix3. LocationofEriogonumshockleyivar.packardaepopulationsknowntobeextant.
Appendix4. OccurrencerecordsforIdahopopulationsof Eriogonumshockleyivar.shockleyifrom
theConservationDataCenterdatabase.
Appendix5. LocationofEriogonumshockleyivar.shockleyipopulationsinIdaho.
PREFACE
EriogonumshockleyiS.Wats,isararespeciesinIdaho,beingdisjunctfromthemainportionofits
distributionintheGreatBasin. Twovarietieshavebeenrecognizedinthestate,theendemicvar.
packardae(Packard'sbuckwheat)andthetypicalvar.shockleyi(Shockley'sbuckwheat). Sincethe
endemicvarietywasfirstrecognizedinthemid-1970's,therehasbeenconsiderableconfusionasto
theidentityofpopulationsinthestate. Thishashinderedconservationplanningforthetwotaxa. To
rectifythissituation,theLowerSnakeRiverDistrict,BLM,andtheIdahoDepartmentofFishand
Game'sConservationDataCenter(CDC)enteredintoacooperativeprojectto(1)conducta
taxonomicassessmentofEriogonumshockleyiinIdahotoaidinidentification,and(2)makea
preliminaryassessmentofitsconservationstatusinthestate.
TheprojectstudyplanalsocalledfordeterminingthedispositionofapopulationofEriogonumfrom
thesummitofWarEagleMountain,intheSilverCityRange,thathadbeenmentionedbyReveal
(1989)asapossiblenewspecies. SearchesbyAnnDeBolt(pre-1994),BobMoseley(in1994),and
JimReveal(in1995)failedtolocatethepopulation. Moreworkisneededonthisentity.
Twosectionscomprisethesummaryofourwork. Section1coversthetaxonomyofEriogonum
shockleyiinIdahoandtheidentificationofthetwovarieties. Itisintheformofamanuscriptthatwe
plantosubmittoGreatBasinNaturalist. Section2isapreliminaryassessmentoftheconservation
statusofthetwovarietiesinIdaho,includingareviewofconservationdesignations,distribution,
habitat,populationbiology,andrecommendationstovariousagenciesregardingtheirmanagementand
conservation.
Asafollow-uptothisproject,IannotatedallcollectionsofE.shockleyiduringlateOctoberandearly
November,1995,atthefollowingherbaria:AlbertsonCollegeofIdaho(CIC),SnakeRiverPlain
Herbarium,BoiseStateUniversity(SRP),BoiseDistrictBI 1,ShoshoneDistrictBLM,andIdaho
PowerCompany. IplantoannotatethoseattheUniversityofIdahoHerbarium(ID)inthespringof
1996.
SECTION1
TAXONOMY
Thissectioncontainsamanuscriptforsubmissiontothepeer-reviewedjournalGreatBasin
Naturalist. Theformandstylediffersomewhatfromtherestofthereportinordertoconformto
editorialguidelinesofthejournal. Forinstance,thetablesandfiguresmentionedinthetextareatthe
endofthesection.
THETAXONOMYOFERIOGONUMSHOCKLEYIS.WATS.
(POLYGONACEAE)INIDAHO
RobertK.Moseley1andJamesL.Reveal2
ABSTRACT.— EriogonumshockleyiiswidespreadintheIhtermountainRegion,with
disjunctpopulationsinsouthernIdaho. Severalofthesedisjunctpopulationshavebeendescribedas
var.packardae,butidentificationproblemshavehinderedconservationeffortsbylandmanagers. We
undertookthisstudytoclarifythetaxonomyofE.shockleyiinIdahotoaidinidentificationand
conservationplanning. Analysisofmorphometricdatausingprincipalcomponentsanalysis
corroboratedobservationsmadeinthefield,thatis,E.shockleyiisrepresentedinIdahobytwo
infraspecifictaxa,var.shockleyiandvar.packardae. Weprovidedescriptionsofthespeciesand
varietiesinIdahoandakeytotheinfraspecifictaxa. Wealsodiscussthebiogeographicsignificance
oftheIdahopopulationsandmakerecommendationsconcerningtheirconservation.
Keywords:Eriogonumshockleyi,Idaho,IntermounxainRegion,taxonomy,rareflora,
Polygonaceae.
EriogonumshockleyiS.Wats,iswidelydistributedthroughouttheIntermountainRegionof
thewesternUnitedStates,whereitoccursonbarrenrocky,clayeyorsandysubstratesinshrublands
orpinyon-junipercommunities(Reveal1985). Idahopopulationsaredisjunctfromthemainrangeto
thesouthbyapproximately100kmandatleastsomepopulationshavedifferentiatedenoughfromthe
typevarietytobeconsideredauniquetaxon,describedasvar.packardaeReveal(Reveal1989). In
additiontoE.shockleyi,volcanicandrelatedlacustrinedepositsalongtheSnakeRiverin
southwesternIdahoarehabitattootherGreatBasindisjuncts,includingPeteriathompsoniaeS.
Wats.,Langloisiapunctata(Cov.)Goodd.,Blepharidachnekingii(S.Wats.)Hackel,Qeomella
plocaspermaS.Wats.,Psathyrotesannua(Nutt.)Grayand MentzeliatorreyiA.Gray. SimilartoE.
shockleyi,Idahopopulationsofthelatterspecieshavedifferentiatedfromtheirsoutherncounterparts
andcomprisetheendemic M.torreyivar.acerosa(M.E.Jones)Barneby.
BothvarietiesofE.shockleyiareconsideredrareinIdaho,withtheendemicvar.packardae
apparentlygloballyrare(PackardandGrimes 1981,ConservationDataCenter1994). Sincethe
presenceoftheendemicvarietywasbroughttotheattentionofbotanistsinthemid-1970's,therehas
beenconsiderabledifficultyidentifyingpopulations(DeBoltandRosentreter1988). Thisproblemhas
confoundedconservationeffortsfortheseraretaxabylandmanagers. Weundertookthisstudyto
clarifythetaxonomyofE.shockleyiinIdahotoaidinconservationplanning.
METHODS
Becausefloweringstemlengthisthemostimportantmorphologicalfeatureseparatingthetwo
taxa(Reveal1989),itwasimportanttocollectallsamplesatorjustpastanthesis,whentheflowering
stemshadfullyelongated. Aftermonitoringselectedpopulationsthroughthelatespringandearly
summer,Moseleymadecollectionsat19ofthe25knownE.shockleyipopulationsinIdahoduring
27-29June1995(Table1). Six populationswerenotsampledbecauseoflimitedaccessorvague
locationinformation.
'ConservationDataCenter.IdahoDepartmentofFishandGame,P.O.Box25.Boise.ID83707.
^DepartmentofBotany,UniversityofMaryland,CollegePark,MD20742-5815.
Intheherbarium,measurements,orcharacterizationsofnon-numericfeatures,weremadeon
eachcollectionfor32morphologicalfeaturesoftheleaves,inflorescencesandflowers(Table2;
Appendix1). Eachsampleconsistedofatleastfiveplants. Aminimumof20measurementswere
madeforeachfeature,usingallplantsinthesample. Themeanofeachnumericfeaturewasusedto
analyzethemorphologicalrelationshipsbetweenthe19collectionsusingprincipalcomponents
analysis(PCA). Non-numericattributesdidnotvaryamongcollectionsand,therefore,werenotused
instudyingmorphologicalrelationships. ThemultivariatestatisticalpackageCANOCO(v.3.12)was
usedforthePCA.
RESULTS
MorphometricAnalysis
Figure1displaystheordinationdiagramofthe19collectionsalongthefirsttwoaxes
extractedbyPCA. Plotsarearrangedintheordinationspacebasedondifferencesinmorphological
attributes,with94%ofthevariationaccountedforbyaxis1. Ofallmorphologicalattributesusedin
theanalysis,fourhadthegreatesteffectonhowcollectionsarealignedalongthisdominantaxis
(reportedas"fractionofvariance,"inparentheses):floweringstemlength(0.99),leafbladewidth
(0.89),leafbladelength(0.78)andpetiolelength(0.75). Therelationshipofcollectionsinthe
ordinationspacewasaffectedlittlebytheotherattributes.
ThisanalysiscorroboratesobservationsoriginallymadebyReveal(1989),whenfewE.
shockleyipopulationswereknowninIdaho. Thatis,E.shockleyiisrepresentedinIdahobytwo
infraspecifictaxa,var.shockleyiandthenarrowendemicvar.packardae. Collectionswithpositive
vlaarlgueersloenavaexsis(FIigruerpere1s)e.ntWviatrh.sohnoeckelxecyeiptbiyonh,avtihnogselwointghernefglaotwievreinvgalsuteesmsha(vmeeashnor=ts1t4e.m2sm(mm)eaannd=
4.2mm)andsmallleavesandcorrespondtovar.packardae. Theexceptionistheintermediate
collection2893. Whenmeasurementsofthiscollectionwereaveragedtogetheritappearstobea
morphologicalintermediatebetweenthe"packardae"and "shockleyi"groups. Inthefield,however,
thepopulationappearstobeamixtureofbothexclusivelylong-stemmedandexclusivelyshort-
stemmedindividuals. Thissituationisdiscussedfurtherbelow.
Taxonomy
—
EriogonumshockleyiS.Wats. Pulvinate-caespitose,mound-formingperennial,0.5-6.2
dmacross,1-5cmhigh,fromawoody,muchbranchedcaudex,thebranchesclothedinmacrescent
leafbasesandterminatedbyrosettes;leavesindensecompactrosettes,theleafblades2-8(10)mm
long, 1-5mmwide,obovate,oblanceolate,elliptic,orspatulate,tomentoseonbothsurfaces,petiole
0-9mmlong,floweringstemsscapose,0-23mmlong,tomentose:inflorescencescapitateand
terminal:bractstomentose,mostlyscalelike,membraneous,ternate,0.5-2mmlong,occasionally3-5
(m8)mmlmongl,ontgomaenndtotshei,ck,thegr(e4e)n:5i(n6v)ollaunccreeolcaotnegetseteetdh,1(-2+)(35)(m4,m5)lpoenrg,hesaeds,siblreooardlpyedciacmeplsanu<l0a.t5e,m2m-,6
glabrous;flowers3-10(13)perinvolucre,paleyellow,occasionallysuffusedwithredatthebase,3
mmlong,denselytomentose,unitedfromonequartertotwothirdsoftheirlength,thesegments
oblong;stamensexerted,thefilaments3^4-mmlong,glabrous,theanthersyellow,0.3-0.5mmlong,
oval;acheneslightbrown,2-3mmlong,denselytomentose,thesubglobosebasetaperingtoashort.
3-angledbeak..
EriogonumshockleyiisdistributedthroughouttheIntermountainRegionfromeast-central
California,eastacrossNevadaandUtah,towesternColorado,andsouthtonorthernArizonaand
NewMexico. ItisdisjunctinsouthernIdaho,withpopulationsscatteredalong135kmoftheSnake
Rivercanyonandthelowervalleysofseveraltributaries(Figure2). AllIdahopopulationsare
highlylocalized,occupyingbarrenhabitatswithinsagebrush-steppe. E.shockleyiisrepresentedin
Idahobytwovarieties,describedbelow. —
EriogonumshockleyiS.Wats.var.shockleyi. Shockley'sbuckwheat. [E.villiflorumA.
Grayvar.candidumM.E.Jones;E.aculevar.shockleyi(S.Wats.)M.E.Jones; E.pulvinanan
Small;E.shockleyisubsp.candidum(M.E.Jones)S.Stokes]. Plantsdenselytolooselypulvinate-
caespitose,0.5-6.2dmacross,2-5cmhigh;leaveswithobovate,oblanceolate,elliptic,orspatulate
blades,3-8(10)mmlong,2-5mmwide,petiole(1)3-9mmlong;floweringstems(6)9-23mmlong
(mean=SP1E4.C2ImMmE)N;SflEoXweArMsIuNniEtDed.o—neqUuSarAt,erItdoahhoal,fOowfythheeierlCeon.g,thT.7SR5ESI,HorseHill,
Moseley2889(ID,SRP),Mancuso1381(ID);T7SR6ES19,SugarValleyBadlands,Moseley2891
(ID,SRP),Rosentreter100,131,3134(CIC,ID,BoiseBLMOffice);T7SR5ES20,Prominent
Buttes,Moseley2892(ED,SRP),Rosentreter137(BoiseBLMOffice);T6SR5ES35,LowerSugar
Valley,Moseley2895(ID,SRP),DeBolt828(CIC,BoiseBLMOffice);T5SR6ES27,Bruneau
Dunes,Moseley2897(ID,SRP);T6SR8ES13,LowerSailorCreek,Moseley2899(ID,SRP),
DeBolt1714(BoiseBLMOffice);ElmoreCo.,T6SR9ES8,SouthofSchoffsIsland.Moseley2898
(ID,SRP),Fites.n.(IdahoPowerCompany);TwinFallsCo.,T7SR13ES9,FossUGulch,Moseley
2900(ID,SRP),Popovich5080(RM,ID,ShoshoneBLMOffice);GoodingCo.,T6SR13ES35,
MaladGorge,Moseley2882(ID,SRP),Rosentreter7920(BoiseBLMOffice),Coles.n.(Idaho
PowerCompany),Popovich5081(RM,ID,ShoshoneBLMOffice).
Thevar.shockleyiisprimarilydistinguishedfromtheendemicvar.packardaebyhavinga
muchlongerfloweringstem,whichisespeciallynoticeableinthefieldwheretheinflorescenses
extendwellabovethecushionofrosettedleaves.Ingeneral,theleavesarelargerinvar.shockleyi,
althoughthisfeatureisvariableandthereisconsiderableoverlapwithvar.packardae. When
surveyinganentirepopulationinthefield,however,theleavesofvar.shockleyiareconsiderably
wider,acharacteristicthatisnotalwaysobviousonherbariumspecimens.
All E.shockleyipopulationsontheeasternendofitsIdahodistributionarevar.shockleyi
(Figure2). PopulationsofbothtaxaoccurintheBruneauRiverdrainageand,inoneinstance,there
appearstobeamixedpopulation(seediscussionbelow). Mostpopulationsofvar.shockleyioccuron
lacustrinedepositsconsistingofacobblydesertpavementonthesurface,over deep,sandy-loam
sediments. Severaloftheeasternpopulationsoccurongraveilydepositsofcakretelyingon
lacustrinesedimentsorbasalt. —
EriogonumshockleyiS.Wats.var.packardaeReveal. Packard'sbuckwheat. Plants
dloenngs,el1y-3commpmacwti,dec,aepseptiitoolsee.0-04.5m-4mdlmonagc,rfoslso,we1ri4ngcmstheimgsh;0-l1e0av(e1s1,w1i3t)hmelmlipltiocngbl(admeesa.n2=-54(.71)mmmm);
flowersuSnPitEeCdIfMrEomNShalEfXtAoMtIwNoEtDhi.rds—ofUtShAei,rIlednaghtoh,.AdaCo.,T1SR1WS32,HalversonLakes,type
locality,Reveal3686(US,BRY.NY,RSA,UC,UTC),Moseley2S85(ID,SRP);T1SR1WS28,
EastofHalversonLakes,Moseley2884(ID,SRP);T1SR1WS36,NorthofPriestRanch,Moseley
2883(ID,SRP);OwyheeCo.,T5SR1ES21,EastofCasdeCreek,Moseley2887(ID,SRP);T7S
R3ES4,ShooflyOoliticLimestone.Moseley2888(ID,SRP),Crimes1742(CIC);T8SR6ES28,
DeerWater-HotCreek.Moseley2890(ID,SRP),DeBolt1743(BoiseBLMOffice);T7SR5ES3,
LittleValley,Moseley2894(ID,SRP);T6SR6ES18,BruneauRim,Reveal3852(BRY,MICH,
NY,US),Moseley2896(ID,SRP);10milessouthofBruneau.Devil'sBathtub,Brights.n.(MIN);
T5SR1ES20,CastleCreekMines.Moseley2886(ID,SRP),DeBolt1465(CIC,BoiseBLMOffice);