Herbs. Leaves entire or serrulate. Verticillasters many flowered, approximate, in terminal capitula or spikes; bracts shorter than verticillasters. Calyx ovoid in flower, tubular in fruit, 10-veined, 2-lipped; upper lip wide, oblong, margin entire or sometimes indistinctly minutely 1-dentate on each side; lower lip subcircular, margin entire, 1/4-1/3 as long as upper lip. Corolla tube dilated at throat, limb 2-lipped, upper lip short 3-lobed; lower lip oblong, margin entire, navicular. Stamens 4, exserted; filaments free, posterior 2 1-dentate at base; anthers 1-locellate. Style apex unequally 2-cleft. Nutlets oblong or ovoid, smooth.

About six species: mainly SE Asia, one species in China.