Perennial, ±species annual; sometimes dioecious; leaf-blades flat or setaceous. Panicle open or contrated. Spikelets 2-several-flowered; upper glume nearly always 3-nerved; lemmas herbaceous or membrnous often with hyaline margins which tend to inflex at maturity, keeled throughout, the keel glabrous or sometimes ciliate, 5--nerved but occasionally the intermediate nerves obscure or obsolescent, obtuse to acute, awnless; floret callus often with a web of fine cottony hirs, the rhachilla glabrous; palea keels scaberulous to sstiffly ciliolate; stemens 3, rarely 1; ovary glabrous. Hilum round to oval.
Cool temperate regions throughout the world, extending through the tropics on mountain tops.
Species ±500. . Habitat variable, but typically meadowland from sea level to above tree line. The genus includes many valuable forage species. The weedy ephemeral P. annua is probably the most cosmopolitan of all grass species.
LITERATURE
Rajbhandari, K.R. 1991. A revision of the genus Poa L. (Gramineae)in the Himalaya. In H. Ohba & S.B. Malla (Eds.), The Himalayan Plants 2: 169--263.
Soreng, R.J. 1991. Systematics of the 'Epiles' group of Poa (Poaceae). Syst. Bot. 16: 507--528.
Veldkamp, J.F. 1994. Poa L. (Gramineae) in Malesia. Blumea 38: 409--457.
