Stems erect or decumbent, branched, 1.5-5(-10) dm, glabrous. Leaves nonaromatic; petiole to 1.7 cm; blade ovate to elliptic or oblong, 1.5-4(-8) × 0.4-2.5 cm, base rounded to cuneate, apex obtuse to rounded or acute, glabrous. Inflorescences lateral cymes, sometimes terminal and axillary spikelike panicles; bracts absent or leaflike and gradually reduced in size distally. Flowers: perianth segments 5, distinct nearly to base, lobes elliptic to oblong, 0.7-1 × 0.5-0.8 mm, apex obtuse or rounded, not keeled, glabrous, not covering fruit at maturity; stamen 1; stigmas 2, 0.1 mm. Utricles depressed-ovoid; pericarp nonadherent, smooth. Seeds 0.8-1.3 mm diam.; seed coat brown-black, dull. 2n = 18.
Erect or ascending annual to 1 m; stems 4-angled, lvs green, ovate to elliptic, 2-7 dm, obtuse or subacute, entire or with an obscure tooth at the widest part, rounded or cuneate to a short petiole; infls axillary, loose, cymosely much branched, many-fld, shorter than or equaling the lvs; cal smooth, its 5 apiculate segments rounded on the back; seeds horizontal, shiny- black, 1 mm wide; 2n=18. Native of Eurasia, occasionally found as a weed in our range
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.