Woody lianas, glabrous or puberulent; branches terete to quadrate, internodes slightly dilate, lenticellate. Leaves opposite or subopposite, entire or serrate. Inflorescences axillary, rarely terminal, cymose, rarely thyrsoid. Flowers bisexual, 5-merous, light yellow. Disk fleshy, inconspicuous, annular or cupular, extrastaminal. Stamens 3; anthers transversely dehiscent, extrorse. Ovary compressed, triangular, 3-locular; ovules axile, 2-6 per locule, binate or imbricate from apex to base per locule. Fruits commonly 3-fascicled capsules or degenerating into only 1 capsule; capsule transversely flattened, thinly leathery, grooved, loculicidally dehiscent. Seeds 2-6, with membranous basal wing, conspicuously 1-grooved at middle, exalbuminous.

About 30 species: mainly in Central and South America and tropical Asia; four species (one endemic) in China.

(Authors: Peng Hua (彭华); A. Michele Funston)