Herbs, shrubs or trees; stems often quadrangular. Leaves opposite, usually simple; stipules absent. Flowers bisexual, usually in racemes or heads. Calyx tubular, with 4–5 lobes or teeth, persistent. Corolla tubular, often irregular; lobes 4–5, imbricate, rarely 2-lipped. Stamens 4, adnate to the corolla tube. Ovary superior, 2-carpellary, entire or 4-lobed, 2–4-locular; style with 2 stigmatic lobes or simple. Fruit a capsule, drupaceous or schizocarpic and separating into four 1-seeded articles or 2 mericarps. 34 gen., widespread, mostly trop. with some temp.