Description from Flora of China
Herbs annual, less often subshrubs, villous or pubescent, rarely glabrous. Stem erect or oblique, usually much branched. Leaves alternate, sessile or subsessile, terete, semiterete, or narrowly complanate, margin entire. Flowers axillary, sessile, usually 1-3-glomerulate, bisexual, sometimes some female, without bractlets. Perianth subglobose, 5-parted, herbaceous, usually hairy; segments incurved, abaxially with transverse, winglike, membranous, veined appendages in fruit. Disk absent. Stamens 5, inserted at base of perianth; filaments flattened; anthers broadly oblong, exserted. Ovary broadly ovoid; ovule subsessile; style obscure; stigmas 2 or 3, filiform, papillose. Utricle depressed globose; pericarp membranous, not adnate to seed. Seed horizontal, globose or ovoid, depressed, slightly emarginate near hilum; testa membranous, glabrous; embryo slender, annular; perisperm not copious.
Scott (Feddes Repert. 89: 101–119. 1978) proposed to submerge Kochia and several other related genera into Bassia. A traditional circumscription of Kochia is accepted here.
Between ten and fifteen species: temperate zones of N Africa, Asia, Europe, and SW North America; seven species in China.