Plant 1-3 dm, mostly villous, from slender rhizomes; basal lvs long-petioled, deeply 3-parted into broadly cuneate-obovate segments, these crenately lobed or incised to above the middle into broad, usually obtuse divisions; involucral lvs sessile, otherwise much like the basal; peduncle solitary; sep 5-6, white or bluish, broadly oblong to oval or elliptic, 8-15 mm; fruiting head short-ovoid, 1 cm or less; achenes densely woolly; style short, glabrous; 2n=16. Wet, rocky ledges, usually in calcareous soil; Lab. to Alas., s. to Que., n. Minn., Colo., and Oreg.; n. Asia. June-Aug.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.