Fls very small, often bracted, greenish, perfect or unisexual, regular or nearly so. Per. 3-5-lobed or 0; in ♀ often accrescent; stamens us. 3-5, free, anthers 2-celled. Ovary 1-celled, ind.; embryo annular. Annual to perennial herbs or shrubs with mostly alt., simple, exstipulate lvs. A cosmopolitan family of some 75 genera and over 500 spp.

Monoecious, ☿, or dioecious herbs or shrubs, rarely small trees, often succulent, glabrous or with vesicular hairs giving a farinose appearance. Lvs generally alternate, sometimes opposite, simple, exstipulate. Fls solitary or in dense cymes aggregated in a spike or panicle, bracteolate, often very small, usually actinomorphic, greenish. Calyx 3-5-lobed, rarely 0, often accrescent at fruiting; lobes usually imbricate. Petals 0. Stamens usually as many as perianth lobes and opposite to them, usually free. Ovary superior, sometimes immersed, 1-locular. Ovule solitary, basal, erect or pendent. Stigmas (1)-2-3. Fr. usually an achene, rarely a berry, occasionally with circumscissile dehiscence. Seed often erect, compressed in 1 plane, non-endospermic, or with endosperm and then embryo curved or coiled round it.