Rhizomatous perennial, 1-3 dm, prostrate or loosely ascending, spreading-hairy, at least on the stem; lvs all opposite, ovate, broad-based and sessile or nearly so, 1.5-3 נ0.8-2 cm, 1-2 times as long as wide, coarsely crenate-serrate with mostly 5-11 teeth per side; racemes axillary, pedunculate, loose, the 10-20 fls evidently pedicellate; pedicels 5-9 mm at maturity, surpassing the subtending, alternate bracts; cor blue, 8-12 mm wide; style 3-5 mm; fr (rarely produced) 3-3.5 mm, broadly triangular-obcordate, with apparently about 6 seeds per locule; 2n=16, 32. A weed in lawns and open, mostly disturbed sites; native of Europe, intr. in much of our range. May-June.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.