Cal very irregular, the 2 lowest lobes resembling the lateral but narrower, triangular, the uppermost lobe broad, rounded, its margins decurrent along the cal-tube, and the whole forming a round, nearly flat cap on the upper side of the cal; cal enlarged in fr; cor 2-lipped, the lower lip deflexed, entire, the upper lip 4-lobed; stamens 4, deflexed along the lower cor-lip; herbs or shrubs with small fls in verticils of 6, subtended by bracteal lvs, forming a slender, terminal, spike-like infl. 150, warm reg.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.