Herbs erect, annual or perennial. Leaves petiolate, dentate. Verticillasters many flowered, crowded, into a terminal or widely spaced capitula along branches; floral leaves similar, smaller, brightly colored; bracteoles minute. Calyx tubular, elongated, straight to slightly curved, 15-veined, throat villous or hirsute; teeth 5, subequal. Corolla red, purple, white, gray, or yellow, spotted, 2-lipped, tube slightly dilated at throat; upper lip narrow, erect to arcuate, apex entire to emarginate; lower lip spreading, 3-lobed, middle lobe largest, emarginate. Anterior stamens fertile, inserted on apical part of corolla tube, exserted; posterior stamens rudimentary, minute, or absent; filaments edentate; anthers linear, versatile, cells 2, divaricate, apex confluent. Style apex 2-cleft, lobes subulate, subequal. Nutlets smooth.
"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."