Ovary bilobed and bilocular, with axile placentation and 2 or 4 ovules per loculus; style long and slender, stigma capitate.
Fruit a bilocular capsule forming 2 cocci with membranous pericarp; dehiscence usually circumscissile.
Corolla yellow or white, usually subrotate to shortly infundibuliform, rarely (not in Africa) hypocrateriform, S (6)–lobed, often pubescent within the tube.
Stamens 2, inserted on the corolla tube, usually with relatively long filaments; anthers introrse.
Seeds angular, reticulate; endosperm absent.
Low shrubs or suffrutices, glabrous or hairy, rarely spinose (not in Africa).
Leaves alternate or opposite, entire or lobed, sessile or petiolate; acarodomatia absent.
Calyx 5–15–lobed, segments entire or divided.