Rvdberg : Rocky Mountain flora 131 



lucre usually 4, oblong, acute, white-tomentose, about 8 mm. 

 long ; flowers about 4 ; lobes of the corolla linear, about 3 mm. 

 long ; pappus very copious, yellowish ; bristles scabrous ; achenes 

 hirsute- villous. 



This species grows on dry hills and tablelands up to an alti- 

 tude of 2300 m. It is nearest related to T. incrmis Nutt, but is 

 distinguished by the narrow, more or less squarrose, and pungent 

 leaves. 



Utah : Rock Creek, 1877, Palmer 264 (type, in herb. Colum- 

 bia University). 



Colorado: Gunnison, 1901, Baker 833. 



Arnica coloradensis sp. nov. 



Perennial, about 2 dm. high and with about 3 pairs of leaves ; 

 stem villous ; basal leaves obovate, nearly sessile, sparingly pubes- 

 cent, 4-5 cm. long ; stem-leaves sessile, ovate or ovate-lanceolate, 

 5-nerved ; heads often solitary or few ; involucre hemispherical ; 

 bracts broadly oblanceolate, acute or acuminate, often tinged with 

 purple, sparingly villous and somewhat glandular, 8-9 mm. long ; 

 rays bright-yellow, over 1 cm. long and 5 mm. wide ; achenes 

 finely strigose. 



This species is perhaps nearest related to A. subplumosa, but 

 differs in the low habit, the single or few heads, and the broad 

 involucral bracts. 



Colorado : 1872, Parry (in herb. Columbia University). 



Carduus Osterhoutii sp. nov. 



Stout ; stem round-angled and striate, more or less tinged 

 with purple, more or less arachnoid-hairy ; leaves pinnately parted 

 about halfway to the midrib, glabrate above, white-tomentose 

 beneath ; lobes at least of the larger leaves oblong, obtuse with a 

 weak spine ; heads 2.5-3 cm. high and about 2 cm. broad ; bracts 

 arachnoid-hairy, linear-lanceolate, without glandular dorsal ridge, 

 gradually tapering into an almost erect, stout, fiat spine ; pappus 

 scabrous. 



This is nearest related to C. Hookerianns and C. oreopliilus, but 

 differs from both in the oblong, obtuse lobes of the larger leaves 

 and the long, stout, flat spines of the involucre. 



Colorado : Red Cliff, Eagle Co., 1902, Osterhont 2706 (type) ; 

 Tennessee Pass, 2640. 



