Herbs, annual, monoecious, delicate, ± farinose. Stems erect, dichotomously branched; branches not jointed, not armed, ultimate branches filiform. Leaves alternate, ± petiolate, succulent; blade oblanceolate to spatulate, base attenuate or sometimes abruptly petiolate, margins entire to hastate, apex obtuse to rounded. Inflorescences dichotomously branched with solitary flowers in axils and terminating branches, rarely in 2-4-flowered clusters. Flowers unisexual, sessile; perianth segments (1-)2-3; staminate flowers with 1-2 stamens; ovary superior; pistillate flowers connate proximally, style 1, stigmas 2. Fruiting structures somewhat flattened utricles; pericarps ± adherent to seeds, tuberculate-papillose, membranous. Seeds vertical, lenticular; seed coat dark brown, smooth, shiny; embryo annular; perisperm copious.