148 



Fig. 117. Poa pratensis L. KENTUCKY BLUE-GRASS.— a, A spikelet; b, a 

 single floret from the same, showing the long cobwebby hairs at the base. 

 Figs. 271 to 278, in Bui. 7, and 533 to 562, in Bui. 17, illustrate other species of 

 the genus Poa. 



117. POA Linn. Sp. PI. 67. 1753. Spikelets 2- to 6-flowered, the uppermost 

 flower imperfect or rudimentary; rachilla articulated above the empty glumes. 

 Empty glumes herbaceous, lanceolate or ovate, 1- to 3-nerved, keeled, persist- 

 ent; flowering glumes herbaceous or membranaceous, lanceolate or ovate, acute 

 or obtuse, awnless, 5-nerved, carinate, falling with the 2-keeled palea and a 

 joint of the rachilla, the dorsal or marginal nerves usually soft-hairy, and often 

 with a tuft of long cobwebby hairs at the base. Stamens 3. Styles distinct; 

 stigmas plumose. Inflorescence paniculate, the branches more or less spreading. 



Species about 120 in both hemispheres, chiefly in the temperate and coolei 

 regions and high mountains of the tropics. North American specits, about 70. 



