Fescue (Festuca) is a genus of about 300 species of perennial tufted grasses, belonging to the grass family Poaceae (subfamily Pooideae). The genus has a cosmopolitan distribution, although the majority of the species are found in cool temperate areas, such as the transition zone and Canada. The genus is closely related to ryegrass (Lolium), and recent evidence from phylogenetic studies using DNA sequencing of plant mitochondrial DNA shows that the genus lacks monophyly. As a result plant taxonomists have placed several species, including the forage grasses, tall fescue and meadow fescue, formerly belonging to the genus Festuca into the genus Lolium.
Fescues range from small grasses only 100 mm tall or less with very fine thread-like leaves less than 1 mm wide, to tall grasses up to 2 m tall with large leaves up to 600 mm (2 ft) long and 20 mm (3/4 in.) broad.
Fescue is sometimes used as feed for horses. However, fescue poisoning, which results from a fungus, is a risk for pregnant mares. Occurring in the last three months of pregnancy, fescue poisoning increases the risk of spontaneous abortion, stillbirths, retained placenta, absent milk production, and prolonged pregnancy. Incorporating legumes into the fescue can be a way to increase livestock gains and conception rates, even if the fescue is infected.
Subgenus Schedonorus, proposed for inclusion in genus Lolium