Cal conspicuously 10-13-nerved, often hairy in the throat, sometimes 2-lipped, the lobes subulate to triangular; cor-tube widened distally, the upper lip flat or slightly concave, straight or somewhat spreading, entire or emarginate, the lower lip deflexed, 3-lobed; stamens 4, ascending under the upper lip, the lower pair the longer; nutlets smooth; herbs of diverse habit. (Acinos, Calamintha, Clinopodium) 100+, widespread.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.