418 Petrak, Die nordamerikanischen Arten der Gattung Cirsium. 
Exsiccata: Petrak, Cirsiotheca universa Nr. 44. 
Distributio: In desertis pratis aridis, arenosis, in 
declivibus lapidosis vel saxosis, collibus sterilibus in civitatibus 
Colorado, New Mexico, Arizona, Texas frequens. 
Vidi e locis sequentibus: 
Colorado: Colorado Springs 25. VII. 1884 Coli. G. W. 
Lettermann H. U. W. — Windsor, Weid County, 3. VIII. 1911 
Coli. G. E. Osterhout H. P. — Livesmore, Larimer County, 30. VII. 
1904 Coli. G. E. Osterhout H. P. 
New Mexico: In pratis siccis prope Nara Visa 10., 18. IX., 
0. X. 1911 Coli. G. L. Fisher H. P„ H. U. W. — Gray, Lincoln 
County, alt. ca. 1800 m 12. VII. 1898 Coli. Miss Josephine Skehan 
Nr. 91 H. N. W. — Organ Mountains, Dona Ana County, alt. 
ca. 1500 m . Coli. E. O. Wooton Nr. 132, H. U. W. 
Arizona: Mustang Mountains 26. VI. 1882 Coli. C. G. 
Pringle H. H., H. B., H. U. W. — Chiricahua Mountains, Stephens 
Ranch, alt. ca. 1700 m, Dry alluvium soil 19. VII. 1907 Coli. 
Miss Bettie Stephens H. P. 
1. Var. Helleri. 
Caulis erectus tenuis 20 — 100 cm altus, arachnoideo-tomen- 
tosus remote vel subdense, raro dense foliosus, vulgo Sim- 
plex, apice monocephalus vel parce brevi- 
terque ramosus, ramis abbreviatis, raro 
subelongatis, subnudis, monocephalis. Folia 
caulina inferiora supra arachnoideo-canescentia, 
subtus albo-tomentosa, quasi in petiolum angustissime 
alatum, margine integerrimum abruptiuscule attenuata, a m - 
bitu oblonga vel ovato-oblonga, ad medium 
vel ad duas tertias fere sinuato-pinnati- 
fida, laciniis am bitu ovatis vel triangulari- 
ovatis, inaequaliter bi- vel tridentatis, 
dentibus t r i a n g u 1 a r i b u s abruptiuscule acu- 
m i n a t i s , spinis subvalidis 1 — 3 mm longis stramineis termi- 
natis; caulina media basi late semiamplexicauli 
sessilia, non vel breviter decurrentia, a m - 
bitu ovato-oblonga, remote sinuato-lobata, 
lobis late triangulari-ovatis abruptiuscule 
acuminatis vel' obtusiusculis inaequaliter brevi- 
terque bi- vel tridentatis, spinis subvalidis 2 — 4 mm longis termi- 
natis; caulina superiora et suprema multo minora, basi plus 
minusve angustata sessilia, oblongo-lanceolata, indivisa, remote 
breviterque dentata. 
Capitula in apice caulis vel ramorum solitaria, ebrac- 
teata vel br acteis 1 — 3 multo brevioribus 
lanceolatis, parce spinuloso-ciliatis suf- 
ful t a , ovata vel ovato-globosa, basi parum. dila- 
tata plus minusve excavata, cum flosculis 4—5 cm longa, 3 — 4 cm 
lata. Involucri parce arachnoidei vel fere glab- 
rescentis foliola exteriora et media lanceolata, apicem 
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