146 UNIVERSITY OF MISSOURI STUDIES [294 



230. ACOMASTYLIS Greene. Yellow mountain 



AVENS. 



569. A. turbinata (Rydb.) Greene [Geuni turbinatum (Rydb) ; 

 Sieversia turbinata (Rydb.) Greene]. Turbinate moun- 

 tain AVENS. 



Above timberline, Arapahoe Peak, 11500-13500 ft. (Dan- 

 iels, 877). 



Wyoming to New Mexico and Arizona. 



570. A. Arapahoensis Daniels. Nov. spec. Arapahoe yellow 

 mountain avens. 



Plant 20- 30 cm. high, the stems (about three in number) 

 puberulent, becoming softly hairy or villous above ; basal leaves 

 ascending, about i dm. long and 3 cm. wide, pinnate, the lower 

 pinnae narrowly falcate, entire, the others mainly ovate in 

 outline, deeply cut into- 2- 7 cuneate lobes, but with occasional 

 little, simple pinnae interspersed with the larger ones; leaves 

 puberulent or glabrate, the margins softly ciliate with white 

 hairs ; rhachis about 3 mm. broad, the base of the petiole about 

 I cm. broad, becoming chaffy and sheathing the stems ; lower 

 half of stem leafless, the upper half bearing two leaves, 23^- 3 

 cm. long, pinnately parted into about 10 narrow lobes, the 

 lowermost broad, stipule-like, and sheathing the stem; pe- 

 duncles softly hairy, 3- 4 in number, subtended by leaves closely 

 resembling the two stem leaves, but smaller, the peduncles 

 themselves occasionally bearing i or 2 bracts, simple or 2- 

 5 pinnately incised ; flowers 2- 2^/^ cm. wide, bright yellow, 

 the petals broadly obovate, five in number; sepals and bract- 

 lets villous at base, 5 each, spreading, becoming erect in fruit 

 or the tips reflexed in age; sepals broadly triangular, about 

 twice as high as the narrower bractlets ; stamens numerous ; 

 styles included in fruit, glabrate; achenes softly villous with 

 white hairs. Foliage, stems, sepals and bractlets purple-tinged. 



The plant differs from A. turbinata (Rydb.) Greene, in its 

 larger size, its softly hairy upper portion, its 3- 4 flowered 

 stems, its broader sepals, which are much longer than the 

 bractlets, and in its larger flowers. This is probably the 



