Stem 4-10 dm, hirsutulous with mostly de flexed hairs; lower lvs long-petioled, pinnately compound, the segments pinnately lobed and incised; upper lvs 3-foliolate with cuneate-obovate segments, or merely 3-lobed; pedicels minutely puberulent and densely hirsute, the hairs commonly 1-1.5 mm long; sep triangular, 4-10 mm; pet white, 3-5 mm; head of achenes subglobose, 12-18 mm; receptacle glabrous or with a few short bristles; achenes 3-5 mm, excluding the style, glabrous or sparsely hirsute; 2n=42. In moist or wet soil; N.S. to s. Ont. and Mich., s. to N.J., w. Va., W.Va., Ky., and Mo. May, June.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.