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 the family Chenopodiaceae, or goosefoot family, 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 microphylla, 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 four tribes and includes about twenty-six genera:

Fossil record

The oldest fossil records for Chenopodioideae are pollen grains recovered from Maastrichtian sediments of the Edmonton Formation in Canada.