Annual or perennial herbs; stems ascending or decumbent, soft or somewhat succulent. Leaves petiolate, opposite, spirally arranged or alternate. Flowers showy, in axillary clusters or racemes, or solitary; sepals 3, rarely 5; petals 5, the uppermost petal free, often lobed, the lower 4 petals fused in lateral pairs. Fruit a fleshy loculicidal capsule; seeds explosively released.
About 1,000 species mostly from tropical and subtropical regions of Asia and Africa, some species in Europe and North America; 3 species naturalised in Australia.
