66 MEMOIES FROM THE DEPARTMENT OF BOTANY OF COLUMBIA UNIVERSITY 



Porter, U. S. Geo\. Surv. 1871: 482; Coulter, ibid. 1872: 756 and 765; Rydb. Bull. 

 Torr. Bot. Club, 24: 5 ; Hook. Fl. Bor. Am. 1 : 190. 



fPotentiUa Pennsylvanka var. piiJclicmma Torr. & Gray, Fl. N. A. 1 : 438. 1840. 



PotentiUa 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. S. Nat. Herb. 3 : 497. 



Macoun, Cat. Can. PL 138 and 517. In part. 



PotentiUa Hippiana pulcherd'ma Wats. Proc. Am. Acad. 8: 555. In part. 1873. 



Coult. Man. Bot. Rocky Mts. 84. In part. 



j\Iacoun, Cat. Can. PL 137. In part. 1888. 



Illustrations: I^hm. Rev. Pot. pi. 22. Plate 22, f. 1; dissection of flower,/. 2; 

 pistil,/. 3; stamen,/. 4.; fruiting hypanthium and calyx,/. 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, crenate. 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, 7^. [ndclierrirna Lehm. has pinnate leaves with approximate 

 leaflets. This was undoul^tedly 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. Hippjiaiia (see below), while P. pidcherrima 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. piikhcrriina had not always pinnate leaves, which, 

 in fact, is rather seldom the case, and consequently included in P. Hippnana pidcherrima 

 also a form Avith 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 numljer varies e^en in the same individual, and therefore 

 many specimens determined as P. gracilis belong to P. pidclierrima. My own from the 

 Black Hills, I unfortunately so labeled. P. pidcherrhna differs from the other members 

 of the group by its leaflets, which are obovate or oblanceolate, mostly obtuse, crenate, 

 silky and green abo\e, 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. 



