Herbs perennial, sometimes subshrubby, branched. Leaves petiolate, dentate. Verticillasters 6-10-flowered, in terminal thyrses; bracts circular-ovate, margin entire, apex cuspidate. Pedicel distinct. Calyx ovoid, hairy outside, glandular, glabrous inside, 2-lipped, enlarged after anthesis, 10-veined; upper lip circular, margin decurrent into tube; lower lip 4-toothed, anterior teeth longer. Corolla purplish or white, 2-lipped, hairy outside, not hairy annulate inside; tube narrowly cylindric, much exserted, straight, not oblique at throat; upper lip reflexed, 3-lobed, middle lobe larger, apex emarginate; lower lip erect, narrow, slightly concave. Stamens 4, declined, much exserted, anterior 2 longer. Style slightly longer than stamens, apex clavate, 2-cleft. Nutlets ovoid to oblong, corrugate.

About five species: SE Asia, Australia; one species in China.

Differing from Orthosiphon only by the long anthers and included by many authors in that genus.