Herbs to shrubs, annual to perennial, rarely dioecious or monoecious, with shiny white bladder cells and sometimes hairs. Stems erect, ascending, or prostrate. Leaves mostly alternate, flat, folded, or with margin rolled downward, fleshy, entire or slightly undulate, not stipulate. Inflorescences of solitary flowers or cymes often resembling fascicles. Flowers bisexual or unisexual, sessile or pedicellate, perigone lobes (3 or)4(-7), inside yellow or green, basally united into a short tube, nut base often angled. Stamens 4 or more, fused basally with perigone tube. Ovary inferior, 2-8-loculed, each locule with one pendulous ovule. Stigmas as many as locules. Fruit a nut, perigone persistent, base turbinate or obovoid, angled or winged, mostly with 4 rows of ornaments, often apically as horns. Seeds subreniform or pear-shaped.

About 60 species: Africa, E Asia, Australia, New Zealand, South America; one species in China.