VOL. II.] 



ROSE FAMILY. 



209 



i. Potentilla arguta Pursh. Tall, or Glandular Cinquefoil. (Fig. 1913.) 



Potentilla arguia Pursh, Fl. Am. Sept. 736. 1814. 

 Geum agrimonioides Pursh, loc. cit. 351. Not 

 P. agrimonioides Bieb. 1808. 



Erect, stout, simple or little-branched 

 above, glandular and villous-pubescent, i-4 

 high. Stipules membranous ; basal leaves 

 ^lender-petioled, pinnately y-n-foliolate; 

 leaflets ovate, oval or rhomboid, obtuse at 

 the apex, the terminal one cuneate, the others 

 rounded at the base and commonly oblique, 

 all sharply incised-dentate; stem leaves 

 short-petioled or sessile, with fewer leaflets; 

 flowers white, densely cymose, terminal, nu- 

 merous, short-pedicelled,5 // -7 // broad; calyx- 

 lobes ovate, acute, shorter than the obovate 

 petals; stamens 25-30, borne on the glandu- 

 lar disk; style nearly basal and fusiform, 

 thickened; achenes glabrous. 



On dry or rocky hills, New Brunswick to the 

 Rocky Mountains, south to New Jersey, Illinois, 

 and Kansas. June-July. 



2. Potentilla argentea L,. Silver)- or Hoary 

 Cinquefoil. (Fig. 1914.) 



Potentilla argentea L. Sp. PI. 497. 1753. 



Stems ascending, tufted, branched, slightly woody at 

 the base, 4 / -i2 / long, white woolly-pubescent. Stipules 

 lanceolate, acuminate; leaves all but the uppermost 

 petioled, digitately 5-foliolate; leaflets oblanceolate or 

 obovate, obtuse at the apex, cuneate at the base, green 

 and glabrous above, white-pubescent beneath, laciniate 

 or incised and with revolute margins, 6 // -i2 // long; 

 flowers cymose, terminal, pedicelled, yellow, 2 // -4 // 

 broad; calyx-lobes ovate, acutish, a little shorter than 

 the obovate retuse petals; stamens about 20; style 

 filiform, terminal; achenes glabrous. 



In dry soil, Nova Scotia and Ontario to Dakota, south to 

 Washington, D. C., Indiana and Kansas. Also in Europe 

 and Asia. May-Sept. 



Potentilla collina Wibel, of Europe, collected at Winona. 

 Minn., and Cambridge, Mass., differs in its more prostrate 

 habit, broader and not revolute leaflets, and larger calyx. 



3. Potentilla rubens (Crantz) Vill. Northern 

 Cinquefoil. (Fig. 1915.) 



Fragaria rubens Crantz, Stirp. Aust. Ed. 2, 2: 75. 1769. 

 Potentilla maculata Pourr. Act. Toloss. 3: 326. 1788. 

 Potentilla Salisbrugensis Haenke in Jacq. Coll. 2: 68. 1788. 

 Potentilla rubens Vill. Prosp. Fl. Dauph. 46. 1779. 



Rootstock prostrate, stems ascending, simple, pubes- 

 cent, 3'-8' high. Stipules membranous; basal leaves 

 slender-petioled, digitately 5-foliolate (rarely 3-foliolate) ; 

 leaflets obovate, obtuse at the apex, narrowed or cuneate 

 at the base, glabrous above, pubescent along the margins 

 and on the veins beneath, green both sides, incisely den- 

 tate, 6 // ~9 // long; flowers few, terminal, loosely cymose, 

 yellow, 6 // -9 // broad; pedicels slender; petals obovate, 

 obcordate, cuneate, yellow, orange-spotted at the base, 

 longer than the ovate acutish calyx-lobes; stamens about 

 20; style filiform, terminal; achenes glabrous. 



Labrador and Greenland to James Bay. Also in northern 

 and alpine Europe. Summer. 



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