Poa

Poa is a genus of grasses, family Poaceae, subfamily Pooideae, comprising about 570 species native to the temperate regions of both hemispheres; its name derives from Greek for fodder. Common names include meadow-grass, bluegrass, tussock and speargrass, and the genus includes both annual and perennial species, most monoecious, reaching a natural height of roughly two to three feet. Leaves are narrow, folded or flat, sometimes bristled, with the basal sheath flattened or sometimes thickened, a blunt or hooded apex and a membranous ligule; the characteristic blue coloration seen in bluegrass species comes from seed heads that appear blue at maturity.