VOL. II.] 



ROSE FAMILY. 



7. Potentilla emarginata Pursh. 

 Arctic Cinquef oil. (Fig. 1919.) 



Potentilla emarginata Pursh, Fl. Am. Sept. 353. 

 1814. 



Stems villous- pubescent, tufted, ascending 

 or erect, i / -4 / high. Stipules ovate or oblong, 

 membranous, mostly obtuse, entire; leaves 3- 

 foliolate, the basal slender-petioled; leaflets 

 obovate, 2 // -6 // long, incised-dentate with 

 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, $"-"]" broad; calyx- 

 lobes ovate, obtuse, pilose, equalling the ob- 

 long bractlets, shorter than the obovate ob- 

 cordate petals; stamens about 20; style terminal, 

 filiform; achencs glabrous. 



Labrador, Greenland and arctic America to 

 Alaska. Also in eastern Siberia and Spitzbergen. 

 Summer. 



8. Potentilla nana Willd. L,ow Cinquefoil. 

 (Fig. 1920.) 



Potenlilla nana Willd. ; Schlecht. Berl. Mag. 7: 296. 1813. 



Villous-pubescent, stems i / -2 / high, tufted, generally i-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. 



9. Potentilla Robbinsiana Oakes. Robbins' Cinquefoil. (Fig. 1921.) 



Potentilla Robbinsiana Oakes; T. & O. Fl. N. A. i: 441. 1840. 



Potentilla minima A. Gray, Man. 122. 1848. 



P.frigida A. Gray, Man. Ed. 5, 154. 1867. Not Vill. 1789. 



Depressed, ^'-2' high, tufted from a thick woody base, 

 villous-pubesceut. 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, i"-\" 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. 



