194 MEMOIRS FROM THE DEPARTMENT OF BOTANY OF COLUMBIA UNIVERSITY 
lanceolate, more or less toothed, about 1 cm. long; basal leaves several, with villous 
petioles 5-10 em. long, pinnate; leaflets 4 or 5 pairs, glabrate or slightly pubescent, 2-5 
em. long, broadly obovate and obtuse, coarsely serrate and incised with ovate teeth; stem 
leaves with fewer more acutish leaflets. Cyme with rather elongated upright branches, 
but with short pedicels, and therefore rather long and narrow. Flowers 10-18 mm. 
in diameter. Hypanthium densely glandular-viseid, villous, not much enlarged in fruit, 
8-10 mm. in diameter. Petals broady obovate, white, turning yellow in drying, a little 
longer than the sepals. Bractlets lanceolate, much smaller than the ovate-lanceolate 
sepals. Stamens about 25; anthers flat, slightly cordate at the base. 
This species resembles D. arguta, but is more slender. The branches of the cyme are 
more elongated, hypanthium smaller, stamens fewer and the leaflets rounder and nearly 
glabrous. The leaves most resemble those of D. glutinosa, from which the plant differs 
mostly in its smaller and white petals and in the narrow cyme. It has been labelled 
Potentilla arguta whenever collected and is apparently a rather rare plant, representing 
that species in the valleys of the northern Rockies. The following specimens have been 
examined : 
Montana: Rydberg; J. H. Flodman, No. 602, in the Elk Mountains ; No. 603 in the 
Spanish Basin; No. 604 (type) near Bozeman ; No. 605 in the Bridger Mountains, all in 
1896; F. L. Scribner, No. 42, 1883. 
Washington: Wilkes’ Exp., No. 817; C. V. Piper, No. 1528. 
Assiniboia: J. Macoun, No. 41, 1880. (?) 
Idaho: A. A. & Gertrude Heller, No. 32380, 1896. 
Wyoming: T. H. Burglehaus, 1894; E. Stevenson, No. 72, 1894; Nelson, No. 2151, 
1896. 
Alberta (?): Macoun, No. 623, 1885 (Kananaskis). 
3. Drymocallis pseudorupestris. 
2 Potentilla rupestris Presl, Epim. Bot. 198. 1849. Not L. 
Potentilla glandulosa var. Nevadensis Wats. Bot. Cal. W178." Un part. VISTO eNot 
P. Nevadensis Boiss. 
Potentilla pseudorupestris Rydberg, Bull. Torr. Bot. Club, 24: 250), 1897. 
Intusrrations: Bull. Torr. Bot. Club, 24: pl. 307. PLATE 103. 
Stem erect, slender, striate, 2-5 dm. high, branched, with slender ascending branches, 
sparingly glandular-villous. Stipules ovate, more or less toothed. Basal leaves several 
with rather short petioles; leaflets 3 or 4 pairs, sparingly and finely pubescent or gla- 
brate, the terminal one obovate, cuneate-flabelliform, the lateral ones obliquely elliptic 
