The Pooideae are the largest subfamily of the grass family Poaceae, with over 4200 species in 14 tribes and roughly 200 genera. They include some major cereals such as wheat, barley, oat, rye and many lawn and pasture grasses. They are often referred to as cool-season grasses, because they are distributed in temperate climate. All of them use the C₃ photosynthetic pathway.

The Pooideae are the largest subfamily of the grass family Poaceae, with over 4200 species in 14 tribes and roughly 200 genera. They include some major cereals such as wheat, barley, oat, rye and many lawn and pasture grasses. They are often referred to as cool-season grasses, because they are distributed in temperate climate. All of them use the C₃ photosynthetic pathway.