Acrotome

Annual or perennial herbs or subshrubs. Leaves entire or toothed. Inflorescences terminal, of spaced few- or densely many-flowered, often glomerate verticils; bracts leaf-like, becoming smaller towards apex of inflorescence; bracteoles linear, often bristle-like and spine-tipped, arcuate and often conspicuous at base of verticil. Calyx as long as or shorter than corolla tube, tubular-campanulate, 10- or 11-nerved, slightly oblique or symmetrical at mouth, equally or unequally 5-11-toothed. Corolla 2-lipped; tube slightly exceeding calyx, tubular, often with a ring of hairs or glands within +/- the middle, pubescent without; upper lip ascending or slightly arched, almost flat, without a fringe of hairs; lower lip spreading, 3-lobed, with middle lobe the largest. Stamens 4, didymous, arising +/- at same level near middle of corolla tube, included within tube, held together by intertwining hairs; filaments of posterior pair +/- straight, those of anterior pair recurved; anthers obovoid or oblong, 1-thecous by confluence, bearing a glandular crest. Ovary 4-lobed, truncate and glandular on truncate surface; style hairy, included with anthers, entire, oblique at apex. Nutlets obovoid, triquetrous, truncate at apex.