Annual or perennial herbs. Leaves stipulate, small, opposite or pseudoverticillate in lower part. Stipules scarious. Inflorescences terminal, dense or lax. Flowers small, bisexual, sometimes perigynous; Sepals entirely scarious, white, not carinate. Petals 5, entire, emarginate or denticulate. Stamens 5 (sometimes fewer), filaments inserted below a disc. Ovary unilocular, ovules few to many; Fruit a capsule dehiscing by 3 valves. Seeds tiny, reniform, translucent.
Asia-Tropical: Tropical Africa: present southern Asia to Australia: present
About 50 species, mostly intropical Africa, throughout southern Asia to Australia. In Malesia four species.