MEMOIRS OF THE NEW YORK BOTANICAL GARDEN. 219 



The genus is distinguished from Potentilla by the club-shaped 

 lateral style, hairy achenes, shrubby habit and adnate scarious stip- 

 ules. It was treated as a subgenus under Potentilla by Torrey and 

 Gray. In wet places, at an altitude of 2000 m. 



Montana: Silver Bow Co., Mrs. Moore; Deer Lodge, 1891, F. 

 D. Kelscy ; Indian Creek, 1884, Tzveedy ; Teton River, 1883, 

 Scribner, ^5. 



*Dasiphora fruticosa tenuifolia (Willd.) Rydb. Mem. Dept. Bot. 



Columbia Univ. 2 : 190 ; Potentilla tenuifolia Willd. ; Schlecht. 



Mag. Ges. Naturf. Fr. Berlin, 7 : 284 ; Potentilla fruticosa 



tenuifolia Lehm. Monog. 31. 



Leaflets narrow, more revolute ; flowers smaller. It grows gen- 

 erally among rocks, but sometimes also in moist ground ; it ascends 

 in the mountains to an altitude of 3000 m. 



Montana: Pony Mts., July 7, 1897, Rydberg; & Bcssey, 4346; 

 Spanish Peaks, 1896, Flodman, j8i ; East Boulder, 1887, Tzveedy, 

 12. 



Yellowstone Park: 1883, 3fiss Mary Comfton; Mammoth 

 Hot Springs, 1897, F. H. Burglehaus. 



Idaho: Mt. Chauvet, July 29, 1897, Rydberg & Bessey, 4345. 



Drymocallis arguta (Pursh) Rydberg, Mem. Dept. Bot. Columbia 



Univ. 2: 192; Potentilla arguta Pursh, Fl. Am. Sept. 736 [111. 



Fl. 2 : 209 ; Torr. & Gray, Fl. N. Am. i : 445 ; Man. R. M. 83] . 



The genus differs from Potentilla in the basal style, ascending and 

 orthotropous seeds, stamens which are arranged in festoons on a thick 

 fleshy disk, and flat anthers. D. arguta belongs to the Eastern 

 United States and the prairie region, but a few specimens which must 

 be referred to it have been collected in Montana. It is found in the 

 valleys, not exceeding an altitude of 2000 m. 



Montana: Northern Montana, F. W. Anderson; Bozeman, 1884, 

 Tweedy ( ? ). 



* Drymocallis convallaria Rydberg, Mem. Dept. Bot. Columbia Univ. 



2 : 193 ; Potentilla convallaria Rydberg, Bull. Torr. Bot. Club, 



24: 249. 



Differs from D. arguta in the smaller flowers, elongated and 

 more glandular inflorescence and less hairy foliage. From D. glan- 

 dulosa, which it most resembles in habit, it is separated by the white 

 or cream-colored petals and the narrow inflorescence. It grows in 

 rich valleys at an altitude of 2000-3000 m. 



