Cal 15-nerved, regular, not hairy in the throat, the lobes triangular, cuspidate; cor strongly 2-lipped, the upper lip small, obovate, shallowly 2-lobed, the lower lip much larger, its lateral lobes bent upward, the terminal lobe broadly dilated; stamens 4, straight, somewhat divergent, exsert, the lower pair slightly the longer; nutlets ovoid, smooth. 15, s. Eur. and Medit. reg. to c. Asia.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.