Rhizome very stout; stems 2-6 dm, mostly simple below the infl; lvs reniform, 3-10 cm wide, shallowly and roundly 5-9-lobed, the lobes sharply serrate; hypanthium campanulate, 1.5 mm, its throat nearly closed by the disk; sep 1.5 mm, alternating with smaller bractlets; 2n=64-100+. Widely distributed in Eurasia, and intr. in New England, N.Y., and se. Can. May-Aug. (A. pratensis) Variable, and often divided into numerous apomictic microspecies. Among these, A. filicaulis Buser, A. glabra Neyg., A. gracilis Opiz, A. monticola Opiz, A. venosa Juz. and A. xanthochlora Rothm., have been ascribed to our range.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.