obovate, 2/’-6’’ long, incised-dentate with 
Von. II.] ROSE FAMILY. 211 
7- Potentilla emarginata Pursh. 
Arctic Cinquefoil. (Fig. 1919.) 
Potentilla emarginata Pursh, Fl. Am. Sept. 353. 
1814. 
Stems villous-pubescent, tufted, ascending 
orerect, 1/-4’ high. Stipules ovate or oblong, 
membranous, mostly obtuse, entire; leaves 3- 
foliolate, the basal slender-petioled; leaflets 
acute teeth, of which the terminal one is gen- 
erally the largest, generally villous on both 
sides, the terminal one narrowed or cuneate, 
the others sometimes broad at the base; flower 
solitary, rarely 2, yellow, 5’/-7’’ broad; calyx- 
lobes ovate, obtuse, pilose, equalling the ob- 
long bractlets, shorter than the obovate ob- 
cordate petals; stamensabout 20; styleterminal, 
filiform; achenes glabrous. 
Labrador, Greenland and arctic America to 
Alaska. Also in eastern Siberia and Spitzbergen. 
Summer. 
8. Potentilla nana Willd. Low Cinquefoil. 
(Fig. 1920. ) 
Potentilia nana Willd.; Schlecht. Berl. Mag. 7: 296. 1813. 
Villous-pubescent, stems 1/—2’ high, tufted, generally 1-flowered. 
Leaves 3-foliolate; stipules broadly ovate, scarious, brown; leaflets 
broadly obovate or orbicular, toothed, the teeth short, rounded, the 
terminal one often the smallest; petals broadly obcordate, exceed- 
ing the ovate acute sepals and the elliptic obtuse bractlets; other- 
wise resembling P. emarginata. 
Labrador, Hudson Bay and arctic America to Alaska, south to the 
Canadian Rocky Mountains. Also in Siberia. Summer, 
g- Potentilla Robbinsiana Oakes. Robbins’ Cinquefoil. (Fig. rg2r.) 
Potentilla Robbinsiana Oakes; T. & G. Fl. N. A. 1: 441. 1840, 
Potentilla minima A. Gray, Man. 122. 1848. 
P. frigida A. Gray, Man. Ed. 5, 154. 1867. Not Vill. 1789. 
Depressed, 14/-2’ high, tufted from a thick woody base, 
villous-pubescent. Stipules ovate, obtusish, loosely villous; 
basal leaves petioled, 3-foliolate, those of the flowering 
stem sessile, small and 3-lobed; leaflets obovate, villous on 
both sides, and especially so beneath, 2’/-4’’ long, deeply 
3-7-dentate above, cuneate or narrowed at the base, obtuse 
at the apex; flowers solitary, terminal, slender-petioled, yel- 
low, about 3’’ broad; sepals and bractlets nearly equal, ob- 
tuse, slightly shorter than the obcordate petals; stamens 
about 20; style terminal, filiform; achenes glabrous. 
White Mountains of New Hampshire. Summer. 
