Annual or perennial herbs or shrubs. Leaves opposite, exstipulate. Inflorescences cymose, dichasially branched. Bracts mostly scarious, rarely herbaceous. Flowers small, herm¬aphrodite, sometimes unisexual. Calyx top-shaped or hemispherical or campanulate, rarely cylindrical, with 5-nerved tube membranous between nerves, and with 5 teeth. Petals 5, white or pink, mostly cuneate, tapering into a wingless claw, without coronal scales. Stamens 10, free. Ovary 1-celled, many-ovuled, with 2 (-3) styles. Capsule usually globular or ovoid, dehiscing to base by 4 (-6) valves. Seeds reniform-auriculate.