Herbs or small shrubs. Leaves basal or cauline, fasciculate or spirally arranged; stipules absent. Flowers usually irregular, in terminal racemes or cymes. Calyx 5-lobed, variously connate into 2 lips. Petals 5, connate into a short tube, imbricate, the lower lobes usually smaller. Stamens 2, adnate to the style forming a column (gynostemium); anther cells finally divaricate and exposing the stigma between them. Ovary inferior, incompletely 2-locular; placentas axile or free-central. Fruit a 2-valved capsule. 5 gen., mostly temp. S. hemisphere.