Glabrous robust perennial (in ours). Leaves alternate, opposite or whorled, entire. Calyx deeply 5-6-lobed. Corolla campanulate, white, pink or mauve. Ovary superior. Fruit a dehiscent capsule. Ovary superior. Capsule valvate.
Worldwide: c. 150 species in temperate and warm regions.
Zimbabwe: 1 taxon.