Description from Flora of China
Plants erect or prostrate herbs, sometimes shrubby. Verticillasters many flowered, widely spaced, in terminal or axillary racemes or panicles; bracts softly bony at base, bright colored. Flowers sometimes pedicellate. Calyx ovoid in flower, suberect or declinate; teeth 5, posterior 1 widest, lateral teeth separate or adnate to posterior tooth forming upper lip; anterior teeth 2, separate or connate, forming lower lip; fruiting calyx tubular, veins elevated, teeth bright colored. Corolla tube campanulate; limb 2-lipped, upper lip short 4-lobed; lower lip longer, declinete, margin entire, ± flat. Stamens 4, declineate, exserted; filaments free, edentate; anthers 1-locellate, flat. Style apex 2-cleft, lobes flat. Nutlets ovoid to oblong, smooth or minutely dotted-reticulate.
About 25 species: Africa, Asia; one species in China.