Annual or perennial herbs or subshrubs. Stipules 0. Leaves opposite, simple, entire. Flowers in axillary pairs, bisexual, actinomorphic. Calyx lobes 5. Petals 5, alternating with calyx lobes. Stamens 5, alternating with petals, attached to a disk. Anthers 2-thecous, dorsifixed. Ovary inferior, 1-locular. Styles 2, free. Ovules numerous. Fruit a capsule. Seeds minute.