Herbs. Stems unbranched. Inflorescences subcapitate or subcorymbose, 3- to several flowered; bract 1; bractlets 2. Calyx tubular or tubular-campanulate, apex 5-lobed. Corolla rose-red or purple, rarely white, bilabiate. Stamens 4, included; anthers 2-celled, both cells fertile, connective broad, apex conical. Ovary 1-locular, parietal placentas 2. Style slender; stigma 2-lobed. Capsule ovoid-globose. Seeds numerous; testa reticulate.

Two species: China, India; both species in China.