The Pooideae are the largest subfamily of the grass family Poaceae, with about 4,000 species in 15 tribes and roughly 200 genera.

They include some major cereals such as wheat, barley, oat, rye and many lawn and pasture grasses.

The Pooideae are the sister group of the bamboos within the BOP clade, and are themselves subdivided into 15 tribes.

[1] Pooidae started diversifying in the Late Eocene, and their radiation was especially intense during the Oligocene and Miocene epochs.

[2] Relationships of tribes in the Pooideae according to a 2017 phylogenetic classification, also showing the bamboos as sister group:[1] bamboos (Bambusoideae) Brachyelytreae Lygeeae Nardeae Duthieeae Phaenospermateae Brylkinieae Meliceae Stipeae Ampelodesmeae Diarrheneae Brachypodieae Littledaleae Bromeae Triticeae Torreyochloinae Phalaridinae Anthoxanthinae Aveninae Brizinae Echinopogoninae Agrostideae Calothecinae Coleanthinae Miliinae Poinae Phleinae Beckmanniinae Cinninae Alopecurinae Ventenatinae Sesleriinae Holcinae Scolochloinae Airinae Aristaveninae Loliinae Dactylidinae Cynosurinae Parapholiinae Ammochloinae