Poaceae subfamilies

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. They are often referred to as cool-season grasses, because they are distributed in temperate climates. All of them use the C3 photosynthetic pathway.

Panicoideae is the second-largest subfamily of the grasses with over 3,500 species, mainly distributed in warm temperate and tropical regions. It comprises some important agricultural crops, including sugarcane, maize (or corn), millet, sorghum, and switchgrass.

Chloridoideae is one of the largest subfamilies of grasses, with roughly 150 genera and 1,600 species, mainly found in arid tropical or subtropical grasslands. Within the PACMAD clade, their sister group is the Danthonioideae. The subfamily includes widespread weeds such as Bermuda grass (Cynodon dactylon), goosegrass (Eleusine indica) or finger grass (Chloris), but also millet species grown in some tropical regions, namely finger millet (Eleusine coracana) and teff (Eragrostis tef).

Oryzoideae (syn. Ehrhartoideae) is a subfamily of the true grass family Poaceae. It has around 120 species in 19 genera, notably including the major cereal crop rice. Within the grasses, this subfamily is one of three belonging to the species-rich BOP clade; it is sister to the other two lineages in the clade, Bambusoideae and Pooideae. All members of the BOP clade use C3 photosynthesis

The Arundinoideae are a subfamily of the true grass family Poaceae with around 40 species, including giant reed and common reed. Unlike many other members of the PACMAD clade of grasses, the Arundinoideae all use C3 photosynthesis. Their sister group is the subfamily Micrairoideae.

The Puelioideae is a subfamily of the true grass family Poaceae with two genera, Guaduella and Puelia, each in its own tribe. Its members grow in the understory of rainforests.

Anomochlooideae is a subfamily of the true grass family Poaceae. It is sister to all the other grasses. It includes perennial herbs that grow on the shaded floor of forests in the Neotropics. There are two genera, Anomochloa and Streptochaeta, each in its own tribe.

Danthonioideae is a mainly Southern Hemisphere subfamily of grasses, containing the single tribe Danthonieae and one unplaced genus, with altogether roughly 300 species. It includes herbaceous to partially woody perennial or annual (less common) grasses that grow in open grasslands, shrublands, and woodlands. It belongs to the PACMAD clade of grasses, but unlike some other lineages in that clade, grasses in the Danthonioideae exclusively use the C3 photosynthetic pathway. Its sister group is the subfamily Chloridoideae.

Pharoideae is a subfamily of the true grass family Poaceae, containing the single tribe Phareae with the two genera Leptaspis and Pharus. Its members grow on the shaded floors of tropical to warm temperate forests.

Micrairoideae is a subfamily of the grass family Poaceae, distributed in tropical and subtropical regions. Within the PACMAD clade, it is sister to subfamily Arundinoideae.