Petrak, Die nordamerikanischen Arten der Gattung Cirsium. 425 
liosus, a medio vel e basi fere ramosissimus, 
ramis plus minusve elongatis subnudis mono- 
vel polycephalis. Folia radicalia utrinque plus 
minusve arachnoidea, supra canescentia, 
subtus albida, in petiolum angustissime alatum, parce 
spinuloso-ciliatum paullatim attenuata, ambitu oblonga 
vel lanceolato-oblonga, ad medium circiter 
sinuato-pinnatifida, laciniis ambitu late 
ovatis vel ovato-triangularibus, -inaequa- 
liter breviterque dentatis, dentibus tri- 
angularibus subobtusis vel abruptiuscule 
acuminatis, spinis subvalidis 1 — 4 mm longis 
terminatis, spinuloso-ciliatis; caulina inferiora et media 
gradatim minora basi semiauriculato-semiamplexicauli sessilia, 
non vel brevissime decurrentia, ambitu 1 a n - 
ceolata vel lineari-lanceolata, remote sinu- 
ato-dentata, dentibus triangularibus acuminatis vel sub- 
obtusis, spinis validioribus, ad 5 mm longis armatis; caulina 
superiora et suprema multo minora, bracteiformia, lanceo- 
lata vel lineari-lanceolata, paullatim attenuata, brevissime 
et remote spinuloso-dentata, ceterum foliis caulinis inferioribus 
similia. 
Capitula in apice caulis et ramorum solitär ia vel 
2 — 3 quasi racemose disposita, ebracteata 
velbracteis 1 — 2 multo minoribus lineari- 
bus, m argine spinuloso-ciliatis suffulta, 
basi non vel perparum dilatata nec excavata, abrupte in pedun- 
culum contracta, ovata, ovato-oblonga vel raro 
fere ovato-globosa, cum flosculis 3 — 3 x / 2 cm longa, 
l x / 2 — 2 cm lata. Involucri glabre sce nt is vel par- 
cissime arachnoidei foliola exteriora et media e basi 
ovato-oblonga abruptiuscule attenuata, apice horizonta- 
liter vel erecto-patentia, spinis infirmis 
stramineis 1 — 2 x / 2 mm longis terminata, 
dorso plus minusve viscido-carinata; interiora 
et intima multo longiora lineari-lanceolata, paullatim acuminata, 
apice plus minusve undulato-curvata nec scariosa. Corollae pur- 
pureae limbus ad medium circiter inaequaliter quinquefidus, 
laciniis angustissimis linearibus subobtusis, a tubo vix vel satis 
distinctus eoque parum longior vel subaequilongus. Filamenta 
omnino dense longiuscule crispule papilloso-pilosa. Pappus sordide 
albus, flosculis parum brevior, setis plumosis apice^ saepe tantum 
scabridis, non vel vix clavellatis. Achaenia matura pallide brunnea, 
canescentia vel fusca, ovato-oblonga vel oblonga, comprcssa, 
5 — 6 mm longa, 2 x / 2 mm lata, subnitida. Bienne ? 
Floret J u n i o — J u 1 i o. 
Synonyma: 
Carduus Tracyi Rydberg in Bull. Torr. Bot. Club XXXII, 
p. 133 (1905). 
