420 ROSACEAE 



65. P. decurrens (S. Wats.) Rydb. Perennial; stems glabrous up to the 

 inflorescence, less than 1 dm. high, ascending; basal leaves pinnate, with 11-13 

 leaflets, which are broadly cuneate, usually 3-toothed at the apex, 1 cm. long or 

 less; cymes 4-10-flowered; sepals lanceolate, acute, 4-5 mm. long; petals obovate, 

 5 mm. long. P. dissecta decurrens S. Wats. Mountains: Utah. Alp. — Mont. 

 Jl. 



66. P. wyomingensis A. Nels. Stems 1-2.5 dm. high, strigose, erect or 

 ascending; basal leaves crowded, pinnate, with 7-19 leaflets, white silky-strigose 

 when young, sometimes glabrate in age; leaflets 1 cm. long or less, the upper 

 pinnatifid, the lower 3-5-fid, with linear or hnear-oblong divisions; sepals ovate- 

 lanceolate, acuminate, 4-5 mm. long; petals broadly obovate, retuse, 6-8 mm. 

 long. P. monidensis A. Nels. Mountains: Wyo.— Mont. — Ida. Suhmont. — 

 Mont. Je-Jl. 



67. P. ovina J. M. Macoun. Stems mostly erect or ascending, usually less 

 than 1 dm. high, strigose, with 2 or 3 reduced leaves, 3-6-flowered; basal leaves 

 crowded, 2-4 cm. long, ajjpressed-hoary, especially when yoimg, pinnate, with 

 7-11 crowded leaflets; leaflets deeply cleft into oblong obtuse lobes; sepals lance- 

 olate, 4 mm. long, acute or acuminate; petals obcordate, about a third longer 

 than the sepals. P. diversifolia pinnatisecfa S. Wats. High mountains: Alta. — 

 Wyo. — Utah. Submont. — Subalp. Je-Au. 



68. P. Drummondii Lehm. Stem erect, 3-6 dm. high, slightly hairy, few- 

 leaved, branched above; basal leaves pinnate, hairy, especially when young; 

 leaflets 5-11, somewhat crowded, often verticillate and the upper confluent, 

 veined, 2-6 cm. long, obovate-cuneate, deeply and sharply serrate; sepals ovate- 

 lanceolate, acuminate, 6-7 mm. long; petals 6-10 mm. long, obcordate, longer 

 than the sepals. Mountains: Alta. — B.C. — n Cahf. — Ida. Submont. — Mont. 

 Jl-S. 



69. P. crinita A. Gray. Stems several, ascending, 2-3 dm. high, often dif- 

 fusely few-branched, silky-pilose; basal leaves many, pinnate, silky-villous 

 (pubescence projecting far beyond the tips of the leaflets), nearly glabrous on 

 the upper surface; leaflets 11-15, approximate, cuneate, 1.5-2 cm. long, toothed 

 at the apex, generally remaining conduphcate; sepals ovate-lanceolate, acute, 

 aliout 4 mm. long; petals obovate, deeply retuse, exceeding the calyx. Dry 

 places: Colo. — Utah — Ariz. — N.M. Submont. Jl-S. 



70. P. paucijuga Rydb. Stems about 2 dm. high, tinged with purple, 

 somewhat villous-hirsute, ascending or decumbent; basal leaves pinnate, with 

 5 leaflets; terminal leaflet broadly obovate, 2-2.5 cm. long, sessile, green, but 

 densely hairy above, white-tomentose and silky beneath, divided two-thirds to 

 the midrib into hnear or oblong, acutish divisions; lateral leaflets similar, but 

 smaller; sepals lanceolate, acute, 5 mm. long; petals yellow, broadly obovate, 

 emarginate, about 6 mm. long. Mountains: se Utah. Subalp. — Alp. Jl. 



71. P. pseudosericea Rydb. Stems several from the caudex, ascending or 

 decumbent, 5-10 cm. high, few-leaved, grayish silky; leaves pinnate, with 5-9 

 approximate leaflets, grayish silky or hirsute above, white-tomentose and silky 

 beneath; leaflets 1-2 cm' long, obovate in outhne, divided to near the midrib 

 into linear obtuse segments; sepals ovate or ovate-lanceolate, 4-5 mm. long; 

 petals obovate, about equalling the sepals. Mountains: Wyo. — Colo. — Nev. 

 Submont. Jl-S. 



72. P. bipinnatifida Dougl. Stems several, erect or ascending, finely white 

 silky-villous, 3-5 dm. higli; basal leaves many, pinnate, with 7-9 approximate 

 leaflets, densely and fln(>ly silky above, white-tomentose beneath; leaflets 2-4 

 cm. long, obovate in outline, pectinately divided to near the midrib into almost 

 Unear, mostly obtuse segments; sepals ovate, 4-5 mm. long; petals obovate, 

 cuneate, truncate, about equaUing or slightly exceeding the sepals. Plains and 

 hills: Man. — Minn. — Colo. — Alta. Plain — Mont. Jl-Au. 



73. P. virgulata A. Nels. Stems 1 or 2, simple, erect, strict, 3-4 dm. 

 high, slightly appressed-pubescent; basal leaves pinnate, with 5-7 leaflets; leaf- 

 lets obovate in outUne, 1-2 cm. long, green and sparingly appressed-silky above, 



