Stems usually ascending to erect, occasionally somewhat viny, 0.6-1 m, glabrous. Leaves all simple, blade often 1-pinnate on distal and middle leaves on vigorous plants 4-13 × 2-9.5 cm; leaflets 2-6 plus additional tendril-like terminal leaflet, ovate, unlobed, 1.5-6 × 1-4.5 cm, not prominently reticulate; surfaces abaxially glabrous and glaucous. Inflorescences terminal and axillary, flowers solitary. Flowers ovoid to broadly urn-shaped; sepals purple or reddish purple, whitish toward tips, ovate-lanceolate, 1.2-2.5 cm, margins not expanded, thick, not crispate, tomentose, tips acute, spreading, abaxially glabrous. Achenes: bodies puberulent; beak 2.5-3.5 cm, plumose. 2 n = 16.