MEMOIRS FROM THE DEPARTMENT OF BOTANY OF COLUMBIA UNIVERSITY 89 
Potentilla nivea uniflora Rydberg, Bull. Torr. Bot. Club, 28: 303. 1896. 
Potentilla nivea Vahliana Wats. Bibl. Index, 1: 298. In part. 
Innusrrations: Lehm. Mon. pl. 18. Puatre 35, f. 3; dissection of flower, f. 4; 
pistil, f. 5; stamen, f. 6; fruiting hypanthium and calyx, f. 7. 
Densely cespitose, the caudex covered with the dark brown scarious stipules and re- 
mains of old leaves. Stems about 5 em. high, more slender than in P. Vahliana, slightly 
villous or tomentose, nearly scapose or with few very small leaves, 1-2-flowered. Leaves 
crowded, ternate, silky or glabrate above, densely white-tomentose beneath; leaflets 
I-1.5 em. long, broadly cuneate or rhombic-obovate, deeply cut from the apex into 
coarse oblong lanceolate teeth. Flowers 15-20 mm. in diameter. Hypanthium white 
or grayish, villous or somewhat tomentose, about 8 mm. in diameter; bractlets oblong or 
lanceolate, nearly equalling the ovate lanceolate acute sepals. Petals yellow, obcordate, 
nearly twice as long as the sepals. 
The true position of this plant is difficult to determine. It may be placed as a va- 
riety of P. nivea or of P. Vahliana or as a species intermediate between the two. Lede- 
bour made it a variety of P. villosa, which it somewhat resembles as to the leaves. It 
has the cespitose habit, short nearly leafless stems, and short wedge-shaped leaves of P. 
Vahliana. Its flowers are nearly of the same size as those of that species, but the petals 
are obcordate, not obreniform, and the sepals and bracts are those of P. nivea, depauperate 
forms of which may grade into it. It is found in the aretic regions from Greenland to 
Alaska and adjacent Asia, but also in the Rocky Mountains to Colorado. Apparently 
all specimens labelled P. nivea Vahliana from the Rockies belong to P. wniflora. It was 
evidently this form that Watson had in mind when he made the statement that P. 
Vahliana was a depauperate few-flowered form of P. nivec. 
Colorado: H. N. Patterson, 1885; No. 195, 1892; C. 8. Crandall; C. F. Baker, No. 
18, 1896; Alice Hastwood, 1892; C. C. Parry; T. 5S. Brandegee, 1880; G. E. Osterhout, 
1893. 
Montana: W. M. Canby, No. 104. 
Oregon: Dy. Lyall, 1861. 
Alberta: J. Macoun, No. 7. 1897. 
British Columbia: John Maecoun, No. 33, 1890. 
Rocky Mountains: FE. Bourgeau, 1853 ; J. Macoun, No. 639, 1885; No. 1481, 1879; 
No: 7332, 1890; Nos. 7331 and 7338, 1891. 
Greenland: H. KH. Wetherill, No. 18, 1894. 
