Cal 13-nerved, strongly 2-lipped, the upper lip broad, shallowly 3-lobed, the lower cleft to the base into triangular-subulate lobes; cor 2-lipped, the tube upcurved, widened to the throat, the upper lip arched, retuse, the lower lip 3-lobed; stamens 4, ascending under the upper lip, not exsert; nutlets subglobose, smooth; shrubs or half-shrubs with narrow, revolute lvs and medium-sized blue or lavender fls in small verticils from the upper axils. 4, se. U.S.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.