Annual; stems prostrate to ascending, to 4 dm, hirsute ±uniformly from base to tip with spreading hairs 0.5-1.5 mm; lvs obliquely ovate-oblong to ovate, 0.5-2 cm, usually half to two-thirds as wide, serrate; fr 1.5-2 mm, strongly 3-lobed, glabrous; seeds gray or pale brown, 1-1.3 mm. Fields, roadsides, and waste ground; N.S. to Mich., s. to N.J., O., and Ind.; also Ariz., and N.M. July-Oct. (E. hirsuta; Chamaesyce p.)
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
Plant: Prostrate annual forb branching from central point; herbage generally pubescent, usually with pilose hairs at nodes, milky sap Leaves: leaves opposite, inequilateral at base, margins widely serrate Flowers: flowers monoecious borne in cyathia; petaloid appendages absent; ovary and capsule glabrous, ~1.5 mm long; seeds reticulately wrinkled to smooth.
From Flora of Indiana (1940) by Charles C. Deam
My only specimen was collected 5 miles northeast of Angola in Steuben County along a roadside just west of a crossroad where there is a small pond at the southwest intersection. Nieuwland collected it in 1910 in South Bend, St. Joseph County.