Poaceae

There are 7 subfamilies:
Subfamily Arundinoideae
Subfamily Bambusoideae
Subfamily Centothecoideae
Subfamily Chloridoideae
Subfamily Panicoideae
Subfamily Pooideae
Subfamily Stipoideae

The family Poaceae, in the Class Liliopsida of the flowering plants, is also known as Gramineae. Plants of this family are usually called grasses. There are about 600 genera and between 9,000-10,000 species of grasses (Kew Index of World Grass Species). Plant communities dominated by Poaceae are called grasslands; it is estimated that grasslands comprise 20% of the vegetation cover of the earth. This family is the most important of all plant families to human economies: it includes the staple food grains grown around the world, lawn and forage grasses, and bamboo, widely used for construction throughout Asia.

The term "grass" is also applied to many grass-like plants not in the Poaceae, leading to plants of the Poaceae often being called "true grasses".