PLANT: Herbaceous perennials and annuals 15 120 cm tall; stems simple or branching, variously pubescent with simple hairs. LEAVES: petiolate, usually ovate or lanceolate, the margins dentate or serrate. INFLORESCENCE: of 1 6 verticils each subtended by involucre of whorled bracts. FLOWERS: perfect, zygomorphic; calyx tubular, 13 15 veined, the teeth 5, the apices aristate or deltoid; corolla white to pink or purple, bilabiate, the tube longer than the lips, the upper lip galeate, arched, or straight, the lower lip spreading, 3 lobed; stamens 2 (and sometimes 2 staminodes), seated within the throat, often exserted, the anther sacs linear; style exserted; stigma unequally 2 lobed. NUTLETS: ovoid, smooth to somewhat reticulate. REFERENCES: Henry, April M. 2003. Lamiaceae. J. Ariz. - Nev. Acad. Sci. Volume 35(2).
Cal tubular, 13-15-nerved, essentially regular, the lobes in our spp. much shorter than the tube; cor strongly bilabiate, the upper lip narrow, entire, straight or curved and often galeate, the lower broader, spreading or deflexed, 3-lobed or with a central projecting tooth; stamens 2, ascending under the upper lip and in most spp. surpassing it; style exsert; erect herbs with lanceolate to ovate lvs and showy fls densely aggregated into head-like clusters terminating the branches or borne also in the upper axils, subtended by foliaceous bracts and mingled with narrow bractlets. 15, N. Amer.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.