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 ovate-lanceolate sepals, both acuminate. Corolla 10-15 nnn. in diameter, yellow; 

 petals obcordate, equalling or slightly exceeding the sepals. 



This species is intermediate between P. fastigiata, Blaschlceana and NuttdlUi. In the 

 form of the leaflets and their dentation it resembles the latter two ; in the pubescence, it is 

 most like the first. It difiers from P. Blaschlceana in the smaller flowers, the longei", more 

 slender, and more open branches of the cyme, and in the much less dense tomentum on 

 the lower surface of the leaves. In the first two characters, it agrees with P. Nuttallii, 

 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 cyme, 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 serve 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, 14443, 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. 

 Potent ilia Nuttallii Lehm. Ind. Sem. Hort. Bot. Hamb. 1852: 12. 1852. 

 Lehm. Ann. ^c-. Nat. (Ill) 19: 364; Rev. Pot. 89; Otto, Garten, u. Blumenz. 

 8: 373*; Walp. Ann. 2: 483. 



AVats. King's Rep. 5: 88; Porter, U. S. Geol. Surv. 1871: 482: Coulter, ibid. 

 1872: 750; Greene, Fl. Fran. 1 : 04 ; Rydb. Bull. Torr. Bot. Club, 24: 8. 



Potentil/a recta Nutt. Gen. 1 : 310. 1818. Not L. 1753. ^ 



Potentilla rigida Nutt. Journ. Acad. Phil. 7: 20. 1834. Not Wall. 1828. 



