Amaranthus blitum L.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
Species Description - Monoecious; stems prostrate to erect, to 6 dm; lvs rhombic-ovate to obovate, 1–3 cm, broadly retuse; petiole about equaling the blade; fls chiefly in axillary clusters, also in short (1–2 cm) terminal panicles; sep of pistillate fls 2, oblong, 1.5–2 mm, at the margins of the fr, a narrower and shorter third one often present at one side; fr broadly elliptic, 1.7–2.2 mm, thin-walled, indehiscent, smooth; seed suborbicular, 1–1.2 mm; 2n=34. An Old-World weed of unknown origin; occasionally found about seaports in our range, and at scattered stations in disturbed sites inland. (A. lividus)