Poaceae (/poʊˈeɪsi.iː, -ˌaɪ/ poh-AY-see-e(y)e), also called Gramineae (/ɡrəˈmɪni.iː, -ˌaɪ/ grə-MIN-ee-e(y)e), is a large and nearly ubiquitous family of monocotyledonous flowering plants commonly known as true grasses. It includes the cereal grasses, bamboos, the grasses of natural grassland and species cultivated in lawns and pasture. Poaceae is the most well-known family within the informal group known as grass.
With around 780 genera and around 12,000 species, the Poaceae is the fifth-largest plant family, following the Asteraceae, Orchidaceae, Fabaceae and Rubiaceae.