Chenopodioideae

Chenopodioideae is a subfamily within the family Amaranthaceae, formerly recognized as the separate family Chenopodiaceae. The group comprises about 1,500 species distributed among roughly 70 genera, including well‑known genera such as Chenopodium, Spinacia, and Atriplex. Members of Chenopodioideae are typically herbaceous plants, shrubs, or small trees, often adapted to saline or arid environments; many possess C3 photosynthesis, while some have evolved C4 pathways.

Plants in this subfamily are characterized by simple, alternate leaves that may be glabrous or covered with mealy, powdery hairs. Flowers are usually small, inconspicuous, and arranged in spikes, panicles, or solitary inflorescences. Each flower typically lacks a perianth and contains five sepals that may be reduced, with both male and female organs present in the same flower (monoecious) or on separate plants (dioecious). The fruit is a utricle or capsule containing several seeds that often have a thin, membranous testa.

Chenopodioideae has a cosmopolitan distribution, predominating in temperate and subtropical regions of the Northern Hemisphere, but also occurring in the Southern Hemisphere and on many islands. Species such as Chenopodium album (lamb’s quarters) are common weeds of disturbed soils, while others like Spinacia oleracea (spinach) and Beta vulgaris subsp. vulgaris (beet) are cultivated for their edible leaves, roots, or seeds. Several taxa are important as forage, salt-tolerant crops, or sources of pigments and medicinal compounds.

Phylogenetic studies using DNA sequencing have refined the circumscription of Chenopodioideae, leading to the inclusion of formerly separate families and the reclassification of some genera. Ongoing research examines its ecological adaptations, especially mechanisms of salt tolerance and drought resistance, which have implications for agriculture and habitat restoration.