258 ROSACEAE (ROSE FAMILY) 



II. Potentilla Nuttallii Lehm. Ind. Sem. Hort. Bot. Hamb. 1852: 12. 

 Stems stout and green, sparsely hirsute, 5-8 dm. high: leaves digitately about 

 7-f oliolate, green and sparsely hirsute; the lower on long petioles; stem leaves 

 gradually reduced; leaflets oblanceolate, toothed or divided nearly halfway 

 to the midrib; stipules nearly entire, lanceolate, acute: cyme open, many- 

 flowered, often broad and flat-topped: calyx hirsute; the bractlets linear- 

 lanceolate, shorter than the long-acuminate sepals: petals obcordate, scarcely 

 longer than the sepals. P. gracilis rigida. (P. etomentosa Rydb. Monog. 

 Pot. probably in so far as our range is concerned; P. jucunda A. Nels. Bull. 

 Torr. Bot. Club 27: 32. 1900.) Colorado to the British boundary. 



15. Potentilla gracilis Dougl. Hook. Bot. Mag. pi. 2984. 1829. Stems 

 usually several, decumbent at base, suberect, more or less branched, silky- 

 villous: leaves 5-7-foliolate, on petioles gradually shorter upward; leaflets 

 oblanceolate or narrowly obovate, green and sparsely pubescent above, 

 densely white-tomentose below, merely toothed or incisely dentate halfway 

 to the midrib ; stipules large, ovate, more or less toothed : cyme rather narrow, 

 or if many-flowered well-branched and broader: sepals lance-ovate, acuminate, 

 surpassing the bractlets but exceeded by the obovate emarginate petals. 

 (This may be a composite species ; as here used it includes the following which 

 are not readily discriminated: P. fastigiata Nutt.; P. pulcherrima Lehm.; 

 P. Blaschkeana Turcz. See descriptions in Rydberg's Monog. Pot. P. filipes 

 Rydb. Bull. Torr. Bot. Club 28: 174. 1901 also is included.) 



16. Potentilla Candida Rydb. Bull. Torr. Bot. Club 24: 6. 1897. Stems 

 low, densely white silky-strigose, 1-2 dm. high: leaves short-petioled, very 

 white silvery-silky on both sides, no tomentum, digitately 7-9-f oliolate ; leaf- 

 lets obovate, deeply incised or cleft into large oblong teeth; stipules ovate, 

 entire: cyme dense: calyx white-silky, the ovate sepals longer than the lanceo- 

 late bracts: petals obcordate, a little longer than the sepals. Rare; north- 

 ern Wyoming, west to Nevada. 



17. Potentilla pectinisecta Rydb. Bull. Torr. Bot. Club 24: 7. 1897. Stem 

 slender, ascending, minutely hirsute, 2-4 dm. high: leaves appressed-silky 

 on both sides, sometimes obscurely tomentulose underneath, slender-petioled, 

 digitately 5-7-foliolate; leaflets obovate, pectinately divided into oblong- 

 linear segments extending well toward the midribs; stipules ovate, often 

 pectinately cleft: flowers in a dense narrow cyme: calyx appressed-silky; the 

 sepals longer than the narrower bractlets and about equaling the obcordate 

 petals. [P. brunnescens Rydb. Bull. Torr. Bot. Club 28: 171. 1901 (?).] 

 Montana and Wyoming to Utah. 



18. Potentilla flabelliformis Lehm. Stirp. Pug. 2: 12. 1830. Stems usually 

 several, slender, decumbent at base but erect, 3-8 dm. high: leaves large, 

 digitately about 7-f oliolate, densely silky above, white-tomentose beneath; 

 leaflets large, 3-5 cm. long, deeply divided or parted into linear lobes with 

 more or less re volute margins; stipules lanceolate or linear: cyme open, with 

 short strict branches: calyx silky-villous ; the sepals triangular-lanceolate, 

 acuminate, much exceeding the small lance-linear bractlets and almost as 

 long as the obcordate petals. P. gracilis flabelliformis. (P. ctenophora Rydb. 

 Bull. Torr. Bot. Club 24: 7. 1897.) Colorado to the British boundary, west 

 to California. 



19. Potentilla subjuga Rydb. Bull. Torr. Bot. Club 23: 397. 1896. Stems 

 more or less tufted, 1-3 dm. high, branched above, rough below with the 

 brown, scarious, persistent stipules: leaves crowded at the base, digitately 

 f>-f'oliolate, with a small additional pair on the petiole; leaflets obovate, deeply 

 incised, the teeth broad and subobtuse, green but silky-villous above, white- 

 tomeiitose beneath; stipules green, ovate, entire: calyx silky-hirsute; its 

 bract^ much shorter than the ovate-acuminate sepals, and shorter than the 

 broadly obeonlate petals. Subalpine; Colorado. 



20. Potentilla quinquefolia Rydb. 1. c. 302. Stems several from a short 

 thick root stock, ascending, usually less than 2 dm. high: leaves crowded at 

 the base, mostly .Vfoliolate, silky-villous above, white-tomentose beneath; 

 leaflet.-, broadly obovute, cleft halfway to the midrib into oblong segmen 



bh; 



1 



