Annuals or slightly to moderately woody perennials. Leaves opposite and often decussate or alternate, simple, usually entire, usually thick and succulent; petiole present or absent; stipules absent. Flowers solitary or in cymes, actinomorphic, usually bisexual, epigynous to perigynous. Hypanthium usually cup-shaped and persistent, often regarded as the tube of the calyx. Sepals 4–5(–6), joined to the rim of the hypanthium. Petals, actually petaloid staminodes, absent or numerous and more or less free and in one to several rows, usually linear and often brightly coloured. Stamens 3 to numerous, usually in several rows. Styles as many as carpels, free or fused at the base; stigmas minute or linear. Fruit a hooded, dehiscent or indehiscent capsule with 3 to many seeds or succulent with many seeds; loculi often roofed.

About 130 genera with some 2500 species, widely distributed but common in South Africa.