Lianes or ± scandent shrubs or small trees, without latex (except in sect. Hippocratea). Leaves opposite or subopposite, petiolate; stipules free or ± united interpetiolarly, usually deciduous, with opposite pairs sometimes connected by ridges. Inflorescence pedunculate, cymose, dichasial or submonochasial, simple or compound, with or without accessory branches, axillary; bracts persistent. Flowers bisexual. Sepals (4) 5, imbricate, free or ± united. Petals (4)5(6), green to white or yellow, often with paler margin, imbricate or valvate in bud. Disk extrastaminal, single or double, varying in shape, free or variously united with other floral parts. Stamens (2)3(4), with filaments often ± broadened below, free or united at the base or sometimes united with the ovary or gynophore; anthers versatile, apical or extrorse, with the thecae ± confluent, dehiscing transversely; pollen simple or rarely in polyads (sect. Hippocratea), not in tetrads. Ovary superior, 3-locular, with 2–20 axile ovules in 2 rows per loculus, sessile or on a gynophore, sometimes immersed in the disk; style simple or absent; stigmas 3, free or ± united, sometimes sessile or very small. Fruit of 3 capsular mericarps united at the base or rarely (not in African species) for most of their length; mericarps dorsiventrally flattened or rarely biconvex, dehiscing by the median suture. Seeds with long stalks, rarely sessile; stalks usually expanded into a wing with the raphe forming a submedian or rarely marginal vein and the thickened integuments forming a vein along the other margin. Germination epigeal or hypogeal. Chromosome number: 2n=56 (3 species).