Annuals, rarely short-lived perennial herbs, young parts farinose with vesicular hairs, which later collapse to scales, or disappear, or plant glandular-hairy, or glabrous. Stem erect to ascending, sometimes prostrate, subangular or sometimes distinctly angular, yellowish, green or green-striped, sometimes red to purple especially in branch and leaf axils. Leaves alternate, except sometimes for the lowermost ones, well-developed; petiole usually shorter than blade, shortening progressively upwards; blade simple to pinnatifid, variously dentate - irregularly serrate - lobed or entire, flat, soft, narrower and entire in bracts. Inflorescence usually a variable panicle or spiciform, formed of clusters of cymosely arranged flowers (glomerules). Flowers small, often dimorphic: terminal flowers bisexual or male, lateral flowers usually female. Perianth lobes 3-5. Stamens 5 or less, usually free. Stigmas 2(-5). Fruit usually falling with perianth. Pericarp usually membranous, sometimes succulent. Seeds horizontal to vertical, lenticular; testa crustaceous, usually lustrous; embryo annular to hippocrepiform.