Somewhat villous-hirsute annual, the stems 1-4 dm, simple or branched especially below, loosely ascending and often rooting below; main lvs opposite, short-petiolate, the blade broadly elliptic or ovate, crenate-serrate, 1-2 cm, 1-1.5 times as long as wide; floriferous part of the stem elongate, with alternate bracts like the lvs, each with a single long-pedicellate axillary fl, the pedicel becoming 1.5-4 cm; cal-lobes lance-ovate, accrescent to 6-8 mm, becoming strongly 3-nerved; cor blue, (5-)8-11 mm wide; fr 5-9 mm wide, 3-5 mm high, divergently lobed, reticulately veined; style 1.8-3 mm; seeds 5-10 per locule, 1.2-1.8 mm, transversely rugose; 2n=28. Native of sw. Asia, intr. in gardens, lawns, roadsides and waste places throughout much of N. Amer. Apr.-Aug. (V. tournefortii)
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.