ROSE FAMILY 417 



divisa Rydb. Dry hilLs: (Black Hills) S.D. — Sask. — Alta. — Colo. Submont. — 

 Alp. Je-Jl. 



39. P. quinquefolia Rydb. Stems generally several, ascending, 1.5-2 dm. 

 high, rather loosely silky-villous ; basal leaves rather many, 5- (seldom 3-) f oliolate, 

 usually with the terminal leaflet short-petiolulate, silky-villous above, white- 

 tomentose beneath; leaflets broaaly obovate, cleft about halfway to the midrib 

 into oblong segments, 1.5-3 cm. long; sepals lanceolate, 4 mm. long; petals obo- 

 vate, emarginate, a little exceeding the sepals. P. nivea pentaphylla Lehm. 

 P. nivea quinquefolia Rydb. P. suhquinata Rydb. Mountains and lulls: Sask. 

 —B.C.— Colo.— Utah. ^ Plain— Alp. J^Jl. 



40. P. modesta Rydb. Stems ascending, about 1 dm. high, several-flowered; 

 basal leaves digitately 5-f oliolate, or 3-f oliolate; leaflets broadly obovate, 1-1.5 

 cm. long, silky, but green above, white-tomentose beneath, deeply cleft into 

 oblong or lanceolate divisions; inflorescence few-flowered, rather dense, the 

 pedicels short; sepals lance-ovate, acute, 3 mm. long; petals 3-4 mm. long, ob- 

 cordate. High mountains: Utah. Submont. — Subalp. My-Jl. 



41. P. Hookeriana Lehm. Stems several from the caudex, 1-2 dm. high, 

 white-tomentose and silky-villous, ascending; leaves ternate, or occasionally 

 with a pair of small extra leaflets, white on both sides, silky-villous above, densely 

 tomentose beneath; leaflets obovate in outline, 1-2 cm. long, deeply cleft to near 

 the midrib into oblong lobes; flowers in small dense cymes, about 8-10 mm. in 

 diameter; sepals lanceolate, acute; petals obcordate, generally a little exceeding 

 the sepals; styles short, a little thickened and glandular at the base. Hills and 

 plains: Sask. — Alta. — Mont. Plain — Submont. Je-Jl. 



42. P. nivea L. Stems several, 1-2 dm. high, more or less tomentose or 

 villous, few-leaved; leaves ternate, glabrate or slightly villous above, densely 

 white-tomentose beneath; leaflets oblong-cuneate or obovate, 2-3 cm. long, 

 generally coarsely crenate; cyme 2-6-flowered; flowers 12-15 mm. in diameter; 

 sepals lanceolate, acute, 5-6 mm. long; petals obcordate, exceeding the sepals, 

 6-8 mm. long. Arctic and alpine regions: Alaska — Greenl. — Que. — Colo.; 

 Eurasia. Alp. — Subalp. Jl-Au. 



43. P. uniflora Ledeb. Stems about 5 cm. high, slightly villous or tomen- 

 tose, 1-2-flowered; leaves crowded, ternate, silky or glabrate above, densely 

 white-tomentose beneath; leaflets 1-1.5 cm. long, broadly cuneate or rhombic- 

 obovate, deeply cut from the apex into coarse oblong-lanceolate teeth; sepals 

 ovate-lanceolate, acute, 4-5 mm. long; petals yellow, obcordate, 6-8 mm. long. 

 Arctic-alpine regions: Alaska — Ore. — Hudson Bay — Colo.; Asia. Alp. — Si&- 

 alp. Je-Au. 



44. P. emarginata Pursh. Stems 2-10 cm. high, generally 1-2-flowered, 

 pilose or softly viUous-hirsute; leaves ternate, pilose on both sides; leaflets 0.5- 

 1.5 cm. long, broadly obovate, with a cuneate base and broad teeth; sepals 

 acute, ovate; petals broadly obcordate, a little exceeding the sepals, 5-8 mm. 

 long. P. nana Willd. Arctic-alpine regions: Lab. — Greenl. — Alaska — Cana- 

 dian Rocky Mountains; Siberia and Spitzbergen. Alp. Jl-Au. 



45. P. flabellifolia Hook. Stems 2-3 dm. high, minutely puberulent, few- 

 leaved; leaves ternate, very thin, short-pubescent or glabrate; leaflets cuneate- 

 flabelliform, deeply serrate, with obtuse teeth, entire towards the base; bractlets 

 oval, obtuse or acutish, equalling the sepals, 5-6 mm. long; petals obovate- 

 cuneate, deeply emarginate, 8-10 mm. long. P. trina A. Nels. Mountains: 

 B.C. — Ida. — c Cahf. Submont. 



46. P. brevifolia Nutt. Stems less than 1 dm. high, slender, 1-2-leaved, 

 glandular-puberulent; leaflets suborbicular, with cuneate base, 2-3-cleft and 

 crenate, 0.5-1 cm. long; sepals broadly ovate and acute or slightly mucronate, 

 4 mm. long; petals a little longer than the sepals, yellow, obovate, and often a 

 little notched. High mountains: Ore. — w Wyo. Mont. — Subalp. Au. 



47. P. tenerrima Rydb. Stems many, very slender, generally tinged with 

 red, 1-1.5 dm. high, sparingly strigose; leaves pinnate, with 2 pairs of leaflets, 

 finely silky and a little grayish-tomentulose beneath; leaflets obovate or oblan- 



