Herbs, shrubs or trees or rarely lianas or epiphytes (not in our region). Leaves opposite or rarely verticillate, with 3—9 longitudinally converging parallel nerves and few to many parallel side veins, the margin entire or toothed. Stipules wanting. Inflorescence consisting of terminal or axillary panicles or corymbs. Bracts sometimes coloured. Flowers hermaphrodite, actinomorphic or the androecium zygomorphic. Hypanthium cupshaped or tubular. Sepals 3—5 or more, sometimes united into a calyptra. Petals imbricate, free or united at the base. Stamens twice as many as or sometimes as many as the petals; filaments free; anthers 2-celled, incurved in the bud, opening by pores or slits, the connective often protruded and appendaged. Ovary inferior to half-inferior, sometimes free in the hypanthium, 2—many-locular or rarely 1-locular. Ovules numerous. Fruit a capsule or berry, enclosed by the hypanthium. Seeds minute. Endosperm wanting. About 4000 species in c. 200 genera in the tropics, mainly on the American continent; only a few species outside the tropics.