Annual herbs. Leaves sessile, not rosetted at base. Inflorescence a few-branched dichasium. Perianth 4- or 5-partite; calyx-lobes shortly united at the base; corolla-tube c. ovoid, lobes spreading, shorter than tube; stamens shortly adnate to corolla-tube, anthers hardly twisting after dehiscence; ovary ovoid, 2-locular, style filiform, stigmas 2, linear. Capsule septicidal, splitting from apex to base, remaining enclosed in persistent calyx and corolla; seeds numerous, small, longitudinally ridged or trabeculate.
About 100 species, from Africa, Madagascar, India through South-east Asia to New Zealand; 2 species in Australia (1 endemic).