414 ROSACEAE 



12. P. glabrata (Lehm.) Rydb. Stems slender, 4-6 dm. high; leaflets 

 2-5 cm. long, oblanceolate or obovate-oblanceolate, glabrous except the veins 

 beneath, cut-toothed about halfway to the midrib; hypanthium strigose; bract 

 lets linear or linear-lanceolate, 3-4 mm. long; sepals ovate, acuminate, 5-7 mm. 

 long; petals obcordate, slightly exceeding the sepals. Valleys: Ore. Wash. 

 w Wyo. Submont. Je-Jl. 



13. P. dascia Rydb. Stem single, erect, 4-7 dm. high, hirsute; leaflets 

 obovate to oblanceolate, 3-10 cm. long, coarsely and rather densely pubescent 

 on both sides, coarsely cut-toothed about halfway to the midrib; hypanthium 

 hirsute, in fruit 7-8 mm. broad; bractlets linear to lanceolate, 4-5 mm. long; 

 sepals lanceolate, 5-6 mm. long; petals obcordate, 7-8 mm. long. Meadows: 

 Wash. Calif. Mont. Submont. Jl-Au. 



14. P. Candida Rydb. Stem low, 1-2 dm. high, densely white silky-strigose; 

 leaflets 7-9, obovate in outline, 2-4 cm. long, rather thick, deeply incised or 

 cleft; flowers about 1 cm. in diameter; hypanthium white-silky; bractlets lance- 

 olate, much shorter than the ovate sepals, which are about 5 mm. long; petals 

 yellow, obcordate, a little exceeding the sepals. Dry places: Nev. s Utah. 

 Submont. Je. 



15. P. Pecten Rydb. Stem 2-3 dm. high, ascending or decumbent at the 

 base, grayish silky-strigose; leaflets 3-4 cm. long, elliptic-ovate or oblanceolate, 

 green and appressed-hairy above, tomentose and silky beneath, dissected one- 

 half to two-thirds to the midrib into oblong acute divisions; bractlets 2-3 mm. 

 long; sepals ovate, acuu mate, 4-5 mm. long; petals broadly obcordate, slightly if 

 at all exceeding the sepals. Mountains: Mont. Wyo. Utah. Submont. Je-Au. 



16. P. Bakeri Rydb. Stem 3-5 dm. high, usually decumbent at the base, 

 loosely hirsute; leaflets oblanceolate, 3-5 cm. long, strongly veined, coarsely ap- 

 pressed-silky on both sides and tomentose beneath, cleft about three-fourths to 

 the midrib into oblong, acutish or obtusish divisions; hypanthium 5-6 mm. 

 broad in fruit; bractlets linear-lanceolate, about 3 mm. long and about half as 

 long as the ovate or ovate-lanceolate sepals; petals obcordate, a little exceed- 

 ing the sepals. Mountain valleys: Wyo. Colo. e Calif. Ida. Submont. 

 Mont. Je-Au. 



17. P. pectinisecta Rydb. Stem slender, 3-4 dm. high, finely silky-strigose 

 or rarely hirsute; leaflets appressed-silky on both sides and sometimes slightly 

 tomentulose beneath, obovate, deeply pectinately divided into oblong or linear 

 segments; hypanthium appressed-silky, in fruit 6-7 mm. broad; bractlets linear- 

 lanceolate, shorter than the broadly lanceolate sepals; petals yellow, obcordate, 

 7-8 mm. long. Dry places: Utah Wyo. n Ariz. Son. Submont. My-Jl. 



18. P. longiloba Rydb. Stem stout, 3-5 dm. high, hirsute-strigose and 

 woolly; leaflets 3-5 cm. long, dissected to near the midrib into linear or linear- 

 lanceolate divisions, loosely villous above, densely white-torn entose beneath: 

 hypanthium in fruit 8 mm. broad; bractlets linear-lanceolate, usually equalling 

 the ovate-lanceolate sepals; petals obcordate, about 8 mm. long. Meadows: 

 w Mont. n Ida. Son. Submont. My-Jl. 



19. P. Blaschkeana Turcz. Stem stout, 5-8 dm. high, sparingly silky, 

 1-2 cm. long; leaves silky or nearly smooth and green above, white-torn entose 

 beneath; leaflets about 5 cm. long, obovate in outline, deeply cleft into linear or 

 oblong divisions, often divergent; hypanthium silky, in fruit often over ] cm. in 

 diameter; bractlets oblong-lanceolate, often much shorter than the broadly 

 lanceolate or ovate sepals; petals broadly obcordate, deeply notched at the apex, 

 much longer than the sepals. Potentilla ctenophora Rydb. Meadows: B.C. n 

 Calif. n Wyo. Alta. Submont. Mont. My-Jl. 



20. P. flabelliformis Lehm. Stem slender, but strict, 4-6 dm. high, silky- 

 strigose; leaves densely silky above, white-tomentose beneath; leaflets 3-5 cm. 

 long, pectinately divided into narrowly linear lobes; hypanthium silky- villous ; 

 bractlets linear-lanceolate, much shorter than the triangular-lanceolate acuminate 

 sepals; corolla 10-12 mm. in diameter; petals obcordate, a little longer than the 

 sepals. Meadows: B.C. Sask. Wyo. n Calif. Son. Submont. Je-Au. 



