Erect or ascending annual 0.5-3 dm, somewhat villous-hirsute below, usually more puberulent above; main lvs ovate or broadly elliptic, palmately veined, 0.5-1.5 cm, 1-2 times as long as wide, crenate-serrate, the lower generally short-petiolate; infl terminal, the bracts alternate; fls subsessile; cor blue-violet, 2-2.5 mm wide; mature pedicels only 1-2 mm; fr 3 mm, obcordate, ciliate-margined, with subglabrous sides; style 0.4-1 mm; seeds (5-)8-11 per locule, 0.8-1.2 mm; 2n=14, 16. Native of Eurasia, established as an inconspicuous weed in gardens, lawns, and fields in much of N. Amer. Apr.-Sept.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.