The Chenopodioideae are a subfamily of the flowering plant family Amaranthaceae in the APG III system, which is largely based on molecular phylogeny, but were included - together with other subfamilies - in family Chenopodiaceae in the Cronquist system. Food species comprise Spinach (Spinacia oleracea), Good King Henry (Blitum bonus-henricus), several Chenopodium species (Quinoa, Kañiwa, Fat Hen), Orache (Atriplex spp.), and Epazote (Dysphania ambrosioides). The name is Greek for goosefoot, the common name of a genus of plants having small greenish flowers. Description The Chenopodioideae are annual or perennial herbs, subshrubs, shrub or small trees. The leaves are usually alternate and flat. The flowers are often unisexual. Many species are monoecious or have mixed inflorescences of bisexual and unisexual flowers. Some species are dioecious, like Spinacia, Grayia, Exomis, and Atriplex. In several species of tribe Atripliceae, the female flowers are without perianth, but enclosed by two bracts. The species with a perianth have up to five tepals. The seed is horizontal or vertical, with annular or horseshoe-shaped embryo. Distribution The subfamily Chenopodioideae is distributed worldwide, but originates from Eurasia. Systematics The genera of this subfamily were formerly classified in family Chenopodiaceae in the Cronquist system. According to Fuentes-Bazan et al. (2012) and based on molecular genetic research, the subfamily comprises 4 tribes and includes about 26 genera: Tribus Anserineae Dumort. (Syn. Spinacieae), with 2 genera: Spinacia L.: with 3 species in Western Asia and North Africa: Spinach (Spinacia oleracea) Blitum, with 12 species nearly worldwide, for example: Blitum capitatum - Strawberry Blite (Syn. Chenopodium capitatum) Blitum bonus-henricus - Good king henry (Syn. Chenopodium bonus-henricus) Blitum virgatum - leafy goosefoot (Syn. Chenopodium foliosum) Tribus Atripliceae C. A. Mey. (Syn. Chenopodieae Dumort.): Fuentes-Bazan et al. (2012) include here also Chenopodium and related genera, as Chenopodiastrum, Lipandra and Oxybasis. Archiatriplex G.L.Chu, with only one species: Archiatriplex nanpinensis G.L.Chu: endemitic in the Chinese province Sichuan. Atriplex L. - saltbush, orache (Syn.: Blackiella, Cremnophyton, Haloxanthium, Neopreissia, Obione, Pachypharynx, Senniella, Theleophyton), with about 300 species worldwide Baolia H.W.Kung & G.L.Chu, with only one species: Baolia bracteata H.W.Kung & G.L.Chu, endemitic in the Chinese province Gansu. Chenopodiastrum S. Fuentes, Uotila & Borsch: with 5 species, for example: Chenopodiastrum hybridum (L.) S. Fuentes, Uotila & Borsch (Syn. Chenopodium hybridum L.) Chenopodiastrum murale (L.) S. Fuentes, Uotila & Borsch - Sowbane, nettle-leaf goosefoot (Syn. Chenopodium murale L.) Chenopodiastrum simplex (Torrey) S.Fuentes, Uotila & Borsch - Maple-leaf goosefoot (Syn.: Chenopodium