Perennial herbs or shrubs, (in Victoria) glabrous. Leaves alternate or in clusters, rarely opposite, sessile or petiolate, entire to toothed; stipules present or absent. Inflorescence axillary or terminal, flowers solitary or in raceme or cyme. Sepals subequal; petals unequal, lower petal longer than others, spurred, clawed, with broad lamina, lower pair linear, lateral pair broader; staminal filaments short, anthers free but cohering by narrow wings, often with appendages, the 2 lowermost anthers with basal nectaries; ovary globose, style clavate, curved at the apex. Fruit a capsule, coriaceous, glabrous, dehiscing into 3 boat-shaped valves; seeds 2-many, smooth, pitted or reticulate.
About 150 species in tropical and subtropical regions; 10 species in Australia.