Erect, pubescent perennial 3-8 dm; lvs all opposite, sessile or nearly so, lanceolate to ovate, broad-based, 2-4 cm, 2-4 times as long as wide, coarsely serrate; racemes commonly 2-4 from the upper axils, 5-10 cm, pedunculate, becoming loose, the bracts shorter than the pedicels; sep (4)5, the lower 2.5-4 mm, the upper usually two-thirds as long; cor blue, 10-13 mm wide; style 6-8 mm; fr obovate, slightly surpassing the cal; 2n=64. Native of Eurasia, occasionally escaped from cult. in the n. part of our range, s. to Md. and O. June, July. (V. latifolia, perhaps misapplied)
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
