ROSACI-AI:. 



[Vol.. II. 



16. Potentilla effusa Dougl. Branched 

 Cinquefoil. (Fig. 1928.) 



P. effusa Dougl.; I.ehm. Nov. Stirp. Pug. 2: 8. 1830. 



Closely related to P. Hippiana and perhaps a 

 mere variety of it. Plant 6 / -i8 / high, diffusely 

 branched above; leaves sometimes interruptedly 

 pinnate, tomentosc-canesceut, but not silky; leaf- 

 lets 5-11, oblong, obtuse at the apex, commonly 

 cuneate at the base, incised dentate, ]^. f -\}^' long; 

 flowers yellow, 3 // ~5 // broad, loosely cymose, yel- 

 low; bractlets shorter than the lanceolate acute 

 calyx-lobes; petals obovate, emargiuate, exceeding 

 the calyx-lobes; stamens about 20; style terminal; 

 achenes glabrous. 



Prairies, western Minnesota (according to Uphani) 

 to Montana and Colorado. Summer. 



17. Potentilla Pennsylvanica L. 

 Prairie Cinquefoil. (Fig. 1929. ) 



Potentilla Pcnnsylranica L. Mant. 76. 1767. 



Stem generally erect, i5'-3o' high, totnentose. 

 Stipules ovate, often much divided; leaves pinnately 

 5-i5-foliolate, grayish tomentose beneath, glabrous 

 above; leaflets oblong or oblanceolate, cleft halfway 

 to the midrib into oblong lobes, margins scarcely 

 revolute; cymes dense, the branches erect; petals 

 yellow, obovate, truncate or slightly emarginate, 

 about equalling the ovate triangular acute sepals 

 and the lanceolate bractlets; stamens 20-25; style 

 terminal, thickened below; acbenes glabrous. 



On prairies, Hudson Bay to the Canadian Rocky 

 Mountains, south to New Mexico. Summer. 



1838. 



Potentilla Pennsylvanica bipinnatifida ( DOUR!. ) T ,V G. 11. N. A. 1:438. 

 Potfntilla bipinnatifida Dougl.; Hook. Fl. Bor. Am. i: 188. 1833. 



Stem slenderer, leaflets divided nearly to the midrib into linear lobes, white tomentose lx 

 neath, silky above; margins scarcely revolute. Hudson Bay to the Northwest Territory, Michigan 

 and Colorado. Perhaps a distinct species. 



Potentilla Pennsylvanica strigosa Pursh, Fl. Am. Sept. 356. 1814. 



Stem usually lower; pubescent with long villous hairs; leaflets with deep narrow divisions, mar- 

 gins revolute. Manitoba and the Northwest Territory to Kansas and New Mexico. Al*o in Siberia. 



18. Potentilla littoralis Rydberg. 

 Coast Cinquefoil. (Fig. 1930.) 



Potentilla lilloralis Rydberg, Bull. Torr. Club, 23: 

 264. 1896. 



Perennial, tufted, stems ascending or decum- 

 bent, branched above, 6 / -2 high, appressed- 

 silky or glabrate. Stipules ovate-lanceolate, 

 cleft or entire, acute; basal and lower leaves peti- 

 oled, pinnately 5-7-foliolate, the leaflets approxi- 

 mate or apparently digitate; leaflets oblanceolate 

 or obovate, incised-pinnatifid into oblong obtuse 

 segments, grayish-pubescent beneath, green and 

 glabrate above, ^ / -2 / J^ / long; flowers yellow, cy- 

 mose, 4 // -5 // broad; petals obovate, equalling or 

 slightly exceeding the ovate acute veined sepals 

 and the lanceolate bractlets; stamens 20-25; style 

 terminal, thickened below; achenes glabrous. 



Coast of Newfoundland and Labrador to Quebec 

 and New Hampshire. June-July. 



