66 MEMOIRS FROM THE DEPARTMENT OF BOTANY OF COLUMBIA UNIVERSITY 
Porter, U. 8. Geol. Surv. 1871: 482; Coulter, ibid. 1872: 756 and 765; Rydb. Bull. 
Torr. Bot. Club, 24: 5; Hook. Fl. Bor. Am. 1: 190. 
? Potentilla Pennsylvanica var. pulcherrima Torr. & Gray, Fl. N. A. 1: 488. 1840. 
Potentilla gracilis Porter & Coult. Fl. Col: 37; Coult. Man. Rocky Mts. 85. In part. 
Eastwood, Fl. Denver, 16; Aven Nelson, Wy. Exp. Sta. Bull. 28: 102, in part; 
Rydberg, Contr. U. 5. Nat. Herb. 3: 497. 
Macoun, Cat. Can. Pl. 138 and 517. In part. 
Potentilla Hippiana pulcherrima Wats. Proc. Am. Acad. 8: 555. In part. 1873. 
Coult. Man. Bot. Rocky Mts. 84. In part. 
Macoun, Cat. Can. Pl. 137. In part. 1888. 
InLustrations: Lehm. Rev. Pot. pl. 22. Puarn.22, f. 1; dissection of flower, f. 2; 
pistil, f. 3; stamen, f. 4; fruiting hypanthium and calyx, f. 5. 
Stem slender, 3-6 dm. high, sparingly silky, branched above. Stipules lanceolate to 
broadly ovate, acute, subentire, or sinuately toothed. Basal leaves in the original form 
pinnate with approximate leaflets, but more commonly digitate with about 5 leaflets, silky 
and green above, generally densely white-tomentose beneath; leaflets oblong, oblan- 
ceolate or narrowly obovate, erenate. Stem leaves smaller and short-petioled. Hypan- 
thium silky, in fruit 5-8 mm. in diameter; bractlets oblong-lanceolate, acute, shorter 
than the ovate-lanceolate sepals, which are acuminate into a nearly subulate tip. Cor- 
olla 12-15 mm. in diameter; petals obovate, cuneate, emarginate, about the length of the 
sepals. 
As originally described, P. pulcherrima Lehm. has pinnate leaves with approximate 
leaflets. This was undoubtedly the reason why Watson united it with P. diffusa Gray. 
As far as I know, that plant is low, ascending, and rather silky and in all respects nearest 
related to P. Hippiana (see below), while P. pulcherrima is tall, upright, with slender 
erect branches and nearest related to P. gracilis and P. fastigiata. Watson, during King’s 
Expedition, observed the fact that P. pulcherrima had not always pinnate leaves, which, 
in fact, is rather seldom the case, and consequently included in P. Hippiana pulcherrima 
also a form with digitate leaves. The only character left to distinguish forms of P. Hip- 
piana from those of P. gracilis was the number of carpels, in the former 10-15, in the lat- 
ter 40. Unfortunately the number varies even in the same individual, and therefore 
many specimens determined as P. gracilis belong to P. pulcherrima. My own from the 
Black Hills, I unfortunately so labeled. P. pulcherrima differs from the other members 
of the group by its leaflets, which are obovate or oblanceolate, mostly obtuse, crenate, 
silky and green above, densely white-tomentose beneath. It grows in the mountains 
and foothills from New Mexico and Nevada to Saskatchewan. No specimens have been 
seen from the Pacific slope. 
