A new species of Psathyrotopsis (Asteraceae, Helenieae) from Coahuila, México

4 Pages·1993·1.4 MB·

by  B L Turner

Phytologia{AvLgxiat 1993)75(2):143-146.
ANEWSPECIES OF PSATHYROTOPSIS{ASTERACEAE, HELENIEAE)
FROM COAHUILA, MEXICO
BillieL. Turner
DepaxtmentofBotany,UniversityofTexas, Austin,Texas 78713 U.S.A.
ABSTRACT
Anewspecies, PsathyrotopsishintoniorumB.L. Turner,isde-
scribedfromnearParras,southern Coahuila,Mexico. It iscloselyre-
latedto P.purpu3iiBrandegee,alsofromsouthernCoahuila. Thefor-
merisreadilydistinguishedbyitslargernearlyentireleavesandlarger
headsonlongerglandular-pubescentpedimcles.
KEY WORDS: Asteraceae, Helenieae, Psathyrotes, Psathyrotop-
sis, Mexico
Routine identification of Mexican Asteraceae has revealed the following
novelty,whichisplacedinthegenus PsathyrotopsisRydberg. Strother&Pilz
(1975) included Psathyrotopsis within the older genus Psathyrotes A. Gray.
Robinson (1981), however,not onlyrecognizedbothgenera,but healsoposi-
tioned themin different subtribes (Gaillardiinaeand Chaenactidinae,respec-
tively). Except for subtribal positions, I agree with Robinson's assessment.
Not only does Psathyrotesproduce achenes with noncarbonized achene walls
(comparedtocarbonizedin Psathyrotopsis),but theseveralspecies described
todatehavetruncatestylebranches(comparedtolinear-lanceolateinPsathy-
rotopsis). With description ofthe present, Psathyrotopsishas three species,
allconfinedto northcentral Mexicoandcloselyadjacent areas.
Psathyrotopsis hintoniorum B.L. Turner, sp. nov.. Figure 1. TYPE:
MEXICO. Coahuila: Mpio. Parras, S ofParras, common on shaleout-
crops, 1405 m, 1 Mar 1993, Hinton et al. 22692(HOLOTYPE: TEX!).
143
144 PHYT L GIA volume 75(2):143-146 August 1993
k,n|..,
.V V 'v\ V ^
KKAi^MiMnr(., H. niprnw
Figure 1. Photograph ofholotypeofPsathyrotopsishintoniorum.
Turner; NewPsathyrotopsisfrom Mexico 145
PsathyrotopsispurpusiiBrandegee similissed caulibus foliatis
(vs.foliisfasciculatisadbsisimcaulis),laminisfoliorumlateovatis
ac integris vel fereintegris (vs. subtiliter crenulatis), capitulis in
pedunculislongioribus (20-30 mmlongisvs.8-20 mm),et bracteis
involucrimanifesteglandulosi-pubescentibus(vs.eglandulosis)dif-
fert.
Suffruticoseperennialwhite-tomentoseherbs 10-20cmhigh. Stems2-5cm
thick, densely white-tomentose. Leaves opposite, densely white-tomentose,
3-6 cm long, 1.5-2.7 cm wide; petioles mostly 1-2 cm long; blades ovate, 3-
nervate, the margins entire to indistinctly undulate. Heads eradiate, 1-3 on
shortterminalpeduncles,theultimatepedunclesglandular-pubescent,2-3cm
long. Receptaclesepaleate,involucrescampanulate,10-12mmhigh,ca.14mm
wide (pressed), the bracts ca. 23, subequal, 2-3 seriate, both densely white-
tomentulose and glandulsir-pubescent. Florets 20-30 per head (estimated),
mm
thecorollasyellow,7-8 long, cylindric,glandular-pubescent, thetubeca.
1 mmlong,thelobes5,ca. 1.2mmlong. Acheneslinear-oblanceolate,3.0-3.5
mm
long, densely pubescent with straight, upwardly-appressed hairs 0.5-1.0
mm long; pappus of numerous bristles 2-5 mm long, these arranged in 2-4
series.
Psathyrotopsis hintoniorum is clearly closely related to P. purpusii but
is markedly different by the several characters noted in the Latin diagnosis.
tAhcecotrydpiengloctaoliSttyro(tcah.er10&0 kPimlzW(19o7f5S)alttihlelo,latCtoearhusipleac,ienseaisrkMnarotwen,oanlryailfrrooamd
station, where it reportedly occurs at ca. 1200 m in light sandy soils at the
footoftalus). AccordingtothemostrecentCartadeMexico(3rdimpression,
1988; ISBN968-892-214-5), EstacionMarteislocatedatca.25°42' N, 101°46'
W,alongthelowermostsouthwesternflanksofSierraLaPaila; Psathyrotopsis
hintoniorumoccurs in the Sierra Parras, which is about 50 km WSW ofthe
SierraLaPaila.
The species is named for the Hinton family present and past, who have
contributedsomuchtoourknowledgeoftheMexicanflora(cf.Turner 1993).
ACKNOWLEDGMENTS
IamgratefultoGuyNesomfortheLatindiagnosis,andtohimandCarol
Todziaforreviewingthemanuscript.
PHYTOLO GIA volume 75(2):143-146 August 1993
LITERATURE CITED
Robinson, H. 1981. ArevisionofthetriballimitsoftheHeliantheae(Aster-
aceae). Smithsonian Contr. Bot. 51:1-102.
Strother,J.&G.Pilz. 1975. TaxonomyofPsathyrotes(Compositae:Senecio-
neae). Madrono 23:24-40.
Turner, B.L. 1993. Jaimehintonia (Amaryllidaceae:Allieae), a new genus
fromnortheastern Mexico. Novon3:86-88.