OF ARTS AND SCIENCES : MAY 13, 1873. 555 



mostly sessile; disk not thickened; stamens 20, rarely 25 ; herba- 

 ceous perennials with conspicuous yellow flowers. 



t Leaves pinnate (or sometimes digitate in P. Hippiana and 

 diver sifolia); carpels usually 10 - 30 ; bractlets shorter than the 

 sepals. 



9. P. Hippiana, Lehm. Densely white-tomentose and silky 

 throughout, the upper surface of the leaves a little darker; stems 

 ascending, 1-1 1° high, slender, branching above into a diffuse cyme ; 

 stipules usually entire ; leaves occasionally digitate, especially in 

 reduced alpine specimens ; leaflets 5-11, cuneate-oblong, 1-2' long, 

 obtuse, incisely toothed at least toward the apex, margin not revolute ; 

 pedicels slender; bractlets narrow; petals 2^-3^" long, exceeding 

 the calyx. — From the Saskatchewan to Nebraska, Colorado, New 

 Mexico, and Northern Arizona. 



Var. pulcherrima. (P. pulcherrima, Lehm. P. diffusa, Gray. 

 P. Pennsylvanica, var. pulcherrima, Torr. & Gray.) Stems 1-2° 

 high ; leaflets 5-9, approximate, crowded, or digitate, the terminal 

 one 1-3' long, the upper surface green and pubescent or subglabrous. 

 — From the Rocky Mts. of British America to New Mexico and 

 Northern Nevada ; Ft. Vancouver (Alvord). 



10. P.effusa, Dougl. Tomentose throughout, with scattered vil- 

 lous hairs; stems ascending, 4- 12' high, diffusely branched above; 

 stipules lanceolate, entire or incised; leaflets 5-11, interruptedly pin- 

 nate, the alternate ones often smaller, cuneate-oblong, coarsely incised- 

 serrate or dentate, the smaller leaflets 3 - 5-toothed ; pedicels slender ; 

 sepals and the much smaller bractlets acuminate, 2-3" long, equalling 

 or exceeding the obcordate petals ; carpels 10. — Saskatchewan 

 (Douglas) ; Rocky Mts. of British America (Bourgeau), and Colorado 

 (Nuttall ; Porter ; Gray). Scarcely more than a form of the last. 



11. P. crinita, Gray. Appressed silky- villous, not at all tomentose ; 

 stems decumbent, 1° long ; stipules lanceolate, entire ; leaflets 9 - 15, 

 mostly folded and falcately recurved, y long, cuneate-oblong, obtuse, 

 coarsely serrate, villous beneath, scarcely so or glabrous above ; cyme 

 loosely paniculate ; sepals acute, nearly 3" long, the bractlets a little 

 shorter ; petals obovate, retuse, exceeding the calyx ; carpels 25-30. 

 — Collected only by Fendler (199), near Santa Fe, New Mexico. 



12. P. Breweri. Alpine ; stems decumbent at base, rather stout, 

 3-10' long ; densely white-tomentose throughout, the calyx and upper 



