Erect perennial to 1 m; lvs opposite or ternate, short-petioled, lanceolate or lance-ovate, 4-10 cm, usually acute or acuminate, very sharply serrate; racemes 1 or few, erect, spike-like, the axis hairy but not glandular; cor blue, hairy in the throat, its lobes 4-5 mm; fr little- flattened, 3 mm, smooth or puberulent, half as long as the persistent style; 2n=34, 68. Native of Europe; intr. in fields, roadsides and waste places from Nf. to N.D., Md., and Ill. June-Aug. (V. maritima; V. spicata, misapplied to plants with obtuse lvs)
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
