Cal 5-parted to about the middle or a little beyond, the narrow segments equal, with ±evident midrib; cor bilabiate, the short upper lip subacutely 2-toothed, the lower lip much longer and 3-lobed; stamens 4; stigmas 2, plate-like; fr loculicidal; low herbs with basal and opposite lvs, or the uppermost lvs alternate, as are the minute or obsolescent bracts of the terminal racemes; fls anthocyanic. 20, Australasia.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.