Herbs annual or perennial. Stems erect, sometimes woody at base. Leaves alternate or sometimes basal leaves forming a rosette. Inflorescences terminal, racemose to corymbose. Calyx 5-lobed; tube fused with ovary at base or to middle. Corolla white, campanulate, 5-lobed. Stamens 5, inserted in corolla tube; filaments very short; anthers obtuse or acute at apex; staminodes 5, linear to ligulate, alternating with corolla lobes. Ovary semi-inferior; ovules numerous, semi-anatropous; style short, stigma obtuse to capitellate. Capsule globose, dehiscing by valves.

Approximately 10 species mostly inhabiting the maritime countries of the southern hemisphere; 1 species occurs in China.