Annual or perennial herbs, often scabrid and turning black on drying. Leaves alternate or opposite, simple. Inflorescence spicate or with flowers in ± spherical clusters or flowers solitary and axillary. Calyx tubular, 10-ribbed, 4-5-lobed. Corolla with cylindric tube and 5 ± equal lobes. Stamens 4; anthers strictly 1-thecous. Fruit a capsule, without a beak.