Annual or perennial herbs and shrubs. Leaves usually alternate, rarely opposite, sometimes succulent, simple, sessile or petiolate, without stipules. Inflorescence an axillary cyme or panicle, rarely of solitary flowers, sometimes with bracteoles; flowers small and greenish, unisexual or bisexual, semi-inferior or hypogynous, actinomorphic. Perianth green, of one whorl of 1–5 segments, sometimes absent. Stamens 1–5. Styles (1–)2–3; stigmas linear or feathery. Ovary 1-celled with 1 ovule. Fruit a utricle, with an achene enclosed in a pericarp.

Contains about 100 genera and 15,000 species worldwide.