Stems weak, 2-4 dm, often decumbent below, glabrous below, finely glandular-puberulent above; lower lvs petioled; main lvs sessile, triangular-ovate or oblong- ovate, 2-5 cm; fls mostly in 1-3 whorls of 4-6 fls each, the pedicels 5-20 mm; cal-lobes narrowly triangular, 4-5 mm; cor-tube 3-4 mm; upper lip normally white, varying to pale blue, 6-10 mm; lower lip bright blue, 8-12 mm; cor-lobes emarginate; upper stamens with pubescent filaments; sterile filament 1 mm, fleshy, projecting at right angles from near the base of the cor-tube; seeds usually 4, 2.5-3 mm, the ventral concavity large and conspicuous; 2n=14. Rich moist woods, especially in alluvial soil; N.Y. to Mich. and s. Wis., s. to w. Va., Ky. and Ark. Apr., May.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.