70 MEMOIRS FROM THE DEPARTMENT OF BOTANY OF COLUMBIA UNIVERSITY 
long, digitate, with about 7 leaflets, silky, but green above, silky and somewhat to- 
mentulose but not white beneath ; leaflets oblanceolate or spatulate, deeply toothed or 
divided nearly half way to the midrib, with oblong, often somewhat divergent teeth. 
Stem leaves smaller, with short petioles. Cyme many-flowered, loose and open. Hypan- 
thium silky, in fruit about 1 cm. in diameter; bractlets lanceolate, a little shorter than 
the oyate-lanceolate sepals, both acuminate. Corolla 10-15 mm. in diameter, yellow; 
petals obeordate, equalling or slightly exceeding the sepals. 
This species is intermediate between P. fastigiata, Blaschkeana and Nuttall. In the 
form of the leaflets and their dentation it resembles the latter two; in the pubescence, it is 
most like the first. It differs from P. Blaschkeana in the smaller flowers, the longer, more 
slender, and more open branches of the eyme, and in the much less dense tomentum on 
the lower surface of the leaves. In the first two characters, it agrees with P. Nuttalli, 
from which it is distinguished by the presence of tomentum, which is, however, very 
sparse, by the more silky pubescence, and by the less prominent venation of the leaves. 
From P. fastigiata it is separated by the tallness of the plant, the open and_ slender 
branched eyme, and the deeper toothing of the leaves. It is most common in the Sas- 
katchewan region, but extends to Colorado, Wyoming and British Columbia. 
The figure given for P. Nuttallii would serye as an illustration of this species, as the 
main difference lies in the pubescence. 
Manitoba: John Macoun, No. 14447, 1896. 
Assiniboia: John Macoun, No. 14448, 1876; Nos. 14442, 14448, 14445, 14449, 
14450, 1896. 
Alberta: John Macoun, Nos. 16723, 16745, 16746, 16748, 1897. 
Montana: J. H. Flodman, No. 566, 1896. 
Washington: Sandberg & Leiberg, 1893; C. V. Piper, No. 2736, 1897. 
Wyoming: Aven Nelson, No. 1858, 1895. 
Colorado: C. F. Baker, No. 16, 1896. 
50. Potentilla Nuttallii Lehm. 
Potentilla Nuttalii Lehm. Ind. Sem. Hort. Bot. Hamb. 1852: 12. 1852. 
Lehm. Ann. Se. Nat. (III) 19: 864; Rev. Pot. 89; Otto, Garten. u. Blumenz. 
8: 373"; Walp. Ann. 2: 483. 
Wats. King’s Rep. 5: 88; Porter, U. S. Geol. Surv. 1871: 482: Coulter, ibid. 
1872: 756; Greene, Fl. Fran. 1: 64; Rydb. Bull. Torr. Bot. Club, 24: 8. 
Potentilla recta Nutt. Gen. 1: 310. 1818. Not L. 1753. 
Potentilla rigida Nutt. Journ. Acad. Phil. 7: 20. 1834. Not Wall. 1828. 
