Herbs or suffrutices. Leaves opposite. Inflorescence terminal but appearing lateral, 1-2-flowered. Flowers actinomorphic. Corolla salver-shaped; lobes overlapping to the left. Ovary of 2 carpels; disk composed of 2 glands. Fruit composed of 2 follicles (although one may abort); follicles cylindric, acute. Seeds oblong, black; testa rugose.
Worldwide: 6 species: 5 in Madagascar, one in India and Sri Lanka