510 Rydberg : Studies on the Rocky Mountain Flora 



dentate on the margin ; the inner bracts less rigid, their tips not 

 spinose but long-attenuate, scarious and somewhat crisp : flowers 

 ochroleucous. 



This species is probably nearest related to C. leiocephalus (D. C. 

 Eaton) Heller but differs in the less divided, less spinose leaves and 

 the bracts which are lacking the long yellow spines on the margins. 

 C. leiocephalus has red flowers. Carduus griseus grows at an alti- 

 tude of 3400 m. 



* 



Colorado: Telluride, 1894, F. Tweedy, J21 (type in U. S. 



Nat. Herb.). 



¥ Carduus pulcherrimus sp. nov. 



Biennial. Stem about 4 dm. high, veiy leafy, grayish-tomentose, 

 especially when young, angled : lower leaves 1 — 1 . 5 dm. long, ob- 

 lanceolate in outline, short-petioled, pinnately divided, bright green 

 and glabrate above, densely white-tomentose beneath ; segments 

 lanceolate or triangular, lobed and toothed with slender spines 3-5 

 mm. long ; the upper leaves similar, sessile and half clasping : heads 

 2.5-3 cm - high, 2.5-4 c ™- broad : outer bracts lanceolate with a 

 narrow glandular ridge, slightly floccose, tipped with yellow spines 

 about 5-7 mm long ; the innermost narrowly lanceolate and with 

 long-attenuate tips : flowers rose-colored. 



In habit this species resembles most .S. undulatus and 5. 

 ochrocentrns, but has smaller heads, narrower bracts and narrower 

 glandular ridge. It is perhaps intermediate between those species 

 and C. canovirais, from which latter it is easily distinguished by 

 the dense tomentum on the lower surface of the leaves. It grows 

 in open woods, etc., at an altitude of about 2500 m. 



Wyoming : Headwaters of Clear Creek and Crazy Woman 

 River, 1900, F. Tweedy, 3048 (type); Medicine Bow, 1898, 

 Elias Nelson, 4396. 



y Carduus oblanceolatus sp. nov. 



Apparently perennial. Stem rather slender, 3-6 dm. high, al- 

 most terete, densely white-tomentose : lower leaves about 1 dm. 

 long, oblanceolate, thick, short-petioled, merely spinulose-dentate 

 or rarely with a few triangular lobes, loosely floccose above, 

 densely white-tomentose beneath, spines slender, 2-5 mm. long ; 

 upper leaves lanceolate, sessile and half clasping : heads 1-3, c anl " 

 panulate, 3-3.5 cm. high, 1.5-2.5 cm. broad: bracts slightly floc- 

 cose at first, with a narrow glandular dorsal ridge, the outer ovate- 

 lanceolate, the middle lanceolate, with a slender divergent spine, 



