236 
IOWA ACADEMY OF SCIENCES. 
ochroleucus, tubes of the corolla eight and one-fourth to one-half 
lines long, lobes three and a half lines long, strongly clavate, 
anther tips acute, bases sagittate, filaments hairy. Achenium light 
brown throughout, with dark longitudinal striae. Pappus of outer 
flowers merely barbellate, inner plumose with strongly clavate tips. 
Type No. 8093, Laramie, Wyoming, Nelson. Laramie,. 
Wyoming, No. 871, from similar locality, should also be 
referred to it, although the latter number approaches C.. 
plattensis-spinosior , except with reference to the size of 
heads, which in C. plattensis-spinosior are somewhat larger. 
Professor Nelson’s 8093 is taller and much less canescently 
tomentose with age. The species is named in honor of 
Prof. Aven Nelson, who has done so much for the botany 
of Wyoming. 
Cnicus Hillii, Canby. 
Cnicus Hillii , Canby Gard. and Forest. 4: 101. 1891. 
C. odoratus , Mulil. C. odoratus, Muhl. Cat. 1 Ed.,. 
Hitchcock Cat. Anth. & Pter. of Ames. 505.. 
Cardans Hillii, Canby. Porter. Bull. Torr. Bot. Club 
5: 344. 1894. 
. Britton & Brown Illustr. FI. N. St. 3: 488.. 
f 4068. 1898. 
Low, sparingly branched perennial; root fusiform, tuberous, eight r 
to twelve inches long; one to two feet high, with purple flowers;, 
stem woolly, the branches bearing single heads; radical leaves,. 
Fig. 15. Cnicus Hillii. 
variable, long; stem leaves, lower spatulate, oblong, with spinulose 
margins to the point of attachment, upper sessileand clasping, usually 
piunatifid, lobes broad and rounded, acute or obtuse, with spinulose 
teeth and stout bristles, leaves slightly hairy on lower surface, upper 
smoothish; heads two one-half inches high, outer bracts of the 
involucre ovate lanceolate with a prominent dorsal glutinous ridgp^ 
