Trees or shrubs, monoecious or dioecious, with or without spines. Stipules paired, caducous. Leaves alternate, simple, often asymmetrical, usually 3-nerved at base. Flowers in small axillary cymes or clusters or solitary, unisexual or bisexual. Sepals 4-5(-8), free or shortly united, persistent. Petals 0. Stamens 4-8, rarely more, free, opposite the perianth lobes. Ovary superior, 1-2-locular; ovules solitary, pendulous; styles 2, terminal, divergent. Fruit dry or thinly fleshy.