Cal tubular, angled or prismatic, the lobes usually shorter than the tube; cor bilabiate, the lower lip arched in the throat, or with 2 elevated ridges partly or wholly closing the orifice; stamens 4, inserted near the middle of the cor-tube; pollen-sacs divergent; style elongate; stigmas 2, plate-like; fr cylindric, loculicidal; ours perennial herbs with rhizomes or stolons; lvs opposite; fls showy, yellow to red or blue, on solitary axillary pedicels. 120, widespread but mainly w. N. Amer.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.