Description from Flora of China
Plants terrestrial, annual or perennial herbs, rarely shrubs. Leaves entire or digitate. Flowers solitary. Pedicel short. Calyx deciduous or persistent. Corolla white, pink, to purple, obliquely campanulate, obscurely bilabiate; lowest lobe longest. Disc glandular. Ovary 2-locular, divided by a false septum almost to apex. Ovules numerous, uniseriate in each locule. Fruit a longitudinally dehiscing capsule, oblong to obconical, 4-sulcate, beaked. Seeds obovate, compressed, winged, fringed, or rarely smooth; testa smooth or rugose.
Twenty-one species: primarily in Africa, India, and Sri Lanka; one species in China.