Herbs, shrubs or (not in Malaysia) trees. Leaves alternate, simple, entire; stipules minute or absent. Flowers in terminal, axillary or lateral racemes, bracteate and bibracteolate, ♀ or unisexual, actinomorphic or zygomorphic, mostly (so in the Malaysian species) monochlamydeous. Tepals 4-5, herbaceous or membranaceous, free, imbricate in bud, coloured during and often also after anthesis, equal or unequal, persistent. Stamens 3 to many, usually inserted on a hypogynous disk, either regularly or irregularly arranged, 1—2-seriate; those of the only or outer series more or less alternating with the tepals; filaments slender, free, persistent; anthers dorsi- or basifixed, dehiscing longitudinally. Ovary superior, composed of 1 or more carpels; these either free or laterally connate. Styles as many as carpels, short, or none, free. Ovules solitary in each carpel, basal. Fruit of 1 or more carpels, juicy or dry. Seed erect; embryo large, peripheric, enclosing the endosperm. Distr. Genera upwards of 20, mostly inhabitants of the tropics of both hemispheres, mainly of America. In Malaysia 3 herbaceous or subshrubby genera, all introduced from tropical America.