Shrub to 1 m, often freely branched; lvs narrowly to broadly ovate, 3-8 cm, usually more than half as wide, obtuse or acute, broadly cuneate to rounded or subcordate at base, the lateral nerves often naked for 1-3 mm at base; infls on axillary peduncles, the lower peduncles progressively longer and to 2 dm, each panicle short-cylindric to ovoid, occasionally branched, often subtended by 1-3 reduced lvs, the individual umbels of the panicle usually separated by distinct internodes; fr depressed-obovoid, 5-6 mm; 2n=24. Upland woods, prairies, and barrens; Que. to Minn., s. to Fla. and Tex. June, July. Var. americanus, occurring mostly in and e. of the mts., has the leaves sparsely pilose only along the nerves beneath. Var. pitcheri Torr. & A. Gray, occurring w. of the mts., has the lvs pubescent across the surface beneath. Var. intermedius Torr. & A. Gray, occurring on the coastal plain from Va. s., differs from var. americanus in its very much branched habit, more numerous infls, and small lvs commonly 2-4 cm.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.