Cal deeply 4-parted, nearly regular; cor strongly bilabiate, the upper lip oblong, acute, the lower lip decurved, nearly flat, shallowly or irregularly 3-lobed; stamens 2 (the upper pair), inserted at the sinus between the cor-lips, the stout filaments straight, exsert; style slender, stigma minute, capitellate; fr loculicidal, suborbicular, slightly flattened; perennial with a rosette of basal lvs from which arises a simple stem with several much reduced lvs and a dense, terminal spike-like raceme of small yellow fls. 7, N. Amer.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.