Annual or perennial herbs, occasionally shrubby, monoecious, often mealy grey from an indumentum of small bladder-hairs, the hairs sometimes collapsed, occasionally glabrous. Leaves alternate, flat, entire or dissected. Flowers small, usually clustered, in axils or terminal panicles, all bisexual or the terminal flowers male or bisexual and lateral flowers female; perianth 3–5-lobed; stamens 1–5, sometimes united at base into a saucer-shaped disc; stigmas 2 or 3. Fruit with thin, membranous (rarely succulent) pericarp surrounding the lenticular to subglobular seed.
About 150 species world-wide; 17 in Australia including 9 naturalised.
The segregate genera Chenopodiastrum S.Fuentes, Uotila & Borsch and Oxybasis Kar. & Kir., erected primarily on molecular evidence but lacking compelling morphological characters are here retained within Chenopodium pending fuller resolution of the group.