Plants dioecious, perennial vines, often woody toward the base, lacking tendrils or spines. Leaves alternate, simple, petiolate. Stipules absent. Inflorescences axillary, racemes or panicles. Flowers actinomorphic, hypogynous; never with bractlets adjacent to the calyx. Calyces of usually 6 free sepals. Corollas absent or of usually 6 free petals, these relatively inconspicuous, white. Staminate flowers with the stamens 6–36, free and distinct, the anthers opening by longitudinal slits. Pistillate flowers with the separate pistils usually 3 or 6, each with 1 locule, the placentation marginal. Style 1 per pistil, short. Fruits 1-seeded drupes. About 80 genera and 500 species, nearly worldwide.

Fruits in the family frequently have the hard inner layer (endocarp) surrounding the seed with unusual shape or ornamentation, giving rise to such common names as cup seed, moon seed, and snail seed.