MEMOIRS FROM THE DEPARTMENT OF BOTANY OF COLUMBIA UNIVERSITY 103 
86. Potentilla tenerrima Rydb. 
Potentilla tenerrima Rydberg, Bull. Torr. Bot. Club, 28: 398. 1896. 
IuuustRations: Bull. Torr. Bot. Club, 23: pl. 275, f. 1-5. Puawr 42, f. 1; fruit- 
ing hypanthium and calyx, f. 2; dissection of flower, f. 3; pistil, f 4; stamen, f. 5. 
Tufted from a perennial root; stems many, very slender, generally tinged with red, 
1-1.5dm. high, sparingly strigose ; stipules linear-lanceolate, acuminate, about 1 em. long, 
the lower scarious and brown. Leaves digitately 3-foliolate, with a pair of smaller leaflets 
below, or pinnate with 2 pairs of leaflets and the terminal leaflet sessile, finely silky 
and a little grayish tomentulose beneath ; leaflets obovate or oblanceolate in outline, 
divided to near the midrid into linear acute segments. Flowers on slender pedicels, nearly 
1 cm. in diameter. Hypanthium silky-strigose, in fruit .6 cm. in diameter; bractlets 
linear, acute, very little shorter than the narrowly lanceolate sepals. Petals obovate, 
slightly retuse, a little exceeding the sepals. Stamens about 20. Style filiform, nearly 
terminal. Achenes smooth. 
This resembles a very slender form of P. rubricaulis, but the plant is usually more 
erect. The segments of the leaflets are also much narrower, as also the bractlets and 
sepals, which are narrower than in any other North American species. 
Colorado: Brandegee, No. 950, 1874 (from Bergen’s Park, type); Hall and Harbour, 
No. 160 (in part, in the Harvard Herbarium); L. H. Pammel, 1895. 
87. Potentilla saximontana Rydberg. 
Potentilla saximontana Rydb. Bull. Torr. Bot. Club, 23: 399. 1896. 
Potentilla nivea Rothrock, Rep. U. 8. Geogr. Sury. 6: 118. Name and locality only. 
1878. Not L. 
IntustRAtions: Bull. Torr. Bot. Club, 23: pl. 277, f. 6-10. Puare 43, f. 6; fruit- 
ing hypanthium and calyx, f. 7; dissection of flower, f. 8; stamen, f. 9; pistil, f. 10. 
Densely cespitose; stems several, 1-3-flowered, less than 5 em. long, silky pubescent. 
Basal leaves numerous, pinnate with 2-8 often approximate pairs of leaflets, silky pubes- 
cent and somewhat tomentose beneath, short-petioled ; leaflets deeply dissected into ob- 
long obtuse or acute segments. Flowers about 1 em. in diameter. Hypanthium densely 
silky; bractlets oblong, obtuse, shorter than the broadly ovate-triangular sepals. Petals 
broadly obcordate, much longer than the sepals. Stamens about 20. Style nearly 
terminal, about equalling the smooth achene. 
It somewhat resembles P. rubricaulis, but is still more cespitose, has much broader 
sepals and leaves, which have mostly much shorter petioles. The leaves are some- 
