Stems 1-1.5 m, from a rhizome; upper lvs sessile, the terminal lfl in each set of 3 broadly rounded to subcordate at the base and broader than long; panicle to 3 dm, loosely branched; filaments slender, colored; anthers 3-4.5 mm; achenes short-stipitate, ellipsoid, 4-6 mm long and a third as thick, the upper side more convex than the lower; style persistent, deflexed. Moist, alluvial thickets; s. Pa. and Md. to n. Va. and W.Va. Late May, June.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.