Herbs, small shrubs or climbers. Leaves alternate or opposite, entire, without stipules. Flowers usually small, bisexual or unisexual, regular, usually sessile within 2 scarious bracteoles, subtended by a scarious bract or floral leaf. Perianth segments 5, scarious or coloured, imbricate, persistent. Stamens 2–5, opposite the perianth segments. Ovary 1-locular, superior; styles 1–3. Fruit a capsule, nut or berry, 1-locular. Seeds 1–many. 65 gen., trop. to temp.