POTENTILLA TENERRIMA n. Sp.
Tufted from a perennial root; stems many, very slender, gener ally tinged with red, I—I dm. high, sparingly strigose ; stipules linear, lanceolate, acuminate, about I cm. long, the lower scarious and brown. Leaves digitately 3-foliolate, with a pair of smaller leaf lets below, or, which is the same, pinnate of 2 pairs and terminal leaflet sessile, finely silky and a little grayish tomentulose beneath ; leaflets obovate or oblanceolate in outline, divided to near the mid rib into linear acute segments ; flowers on slender pedicels, nearly cm. in diameter ; calyx silky-strigose, in fruit 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 2 D; style filiform, nearly terminal ; achenes smooth.
(Plate 275, figs. 1-5).
It resembles a very slender form of the preceding, but the ter minal leaflets, as in the two next, are always only three. The seg ments of the leaflets are also much narrower, as also the bracts 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).