Stems generally simple, erect. Leaf blade: primary leaflets 7-13 or not distinctly differentiated; leaflets and larger lobes narrowly linear to narrowly lanceolate, 1-6 cm × 0.5-6(-10)mm; surfaces nearly glabrous to densely silky-hirsute. 2 n = 16.

Flowering spring-summer. Moist mountain meadows, prairies, and open woods and thickets; 700-3300 m; Ariz., Colo., Idaho, Mont., N.Mex., Oreg., Utah, Wash., Wyo.

Plants from the vicinity of Flagstaff, Coconino County, Arizona (and in post-1943 identifications, some from New Mexico), with the lobes of the leaflets ca. 1 mm wide, were recognized by R. O. Erickson (1943) as C. hirsutissima var. arizonica , but these scarcely appear to constitute a distinct taxon; some plants from Washington, Oregon, Colorado, and elsewhere have leaflets quite as narrowly lobed, and other plants in the Flagstaff area have more widely lobed leaflets. The widely spreading leaves allegedly characteristic of C. hirsutissima var. arizonica likewise occur elsewhere in the range of the species. Clematis hirsutissima var. hirsutissima , as circumscribed here, is highly variable in the density of leaf pubescence throughout most of its range.