Perennial from a stout root, erect or decumbent, leafy, 3-7 dm; lvs digitate, the larger with 5 lfls, these oblanceolate to obovate, 3-5 cm, deeply and often irregularly serrate above the entire cuneate base, villous or sericeous beneath, with or more often without a thin tomentum; infl much-branched; fls numerous, 8-10 mm wide; pet yellow, about equaling the sep; stamens 20; cal and bractlets accrescent, to 15-20 mm; achenes wrinkled, with conspicuous longitudinal ridges; 2n=28, 42, 56. Native of Eurasia, found as an occasional weed in dry soil and waste places in our range. June-Sept.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.