Elymus

Elymus is a genus of perennial grasses, family Poaceae, subfamily Pooideae, tribe Triticeae, comprising approximately 150 species with Plants of the World Online accepting 173 species and 19 hybrids as of a 2024 count; the genus is cosmopolitan, represented across all continents. Common names include couch grass, wild rye and wheatgrass, and the genus is related to rye, wheat and other cereal grains; its name derives from the Greek elumos, referring to foxtail millet. Established by Carl Linnaeus with Elymus sibiricus as the type species, the genus carries considerable taxonomic complexity, with numerous historical synonyms reflecting the reclassification of species into other genera over time.