620 POACE.E. 



130. (350). POA L. Sp. PI. or (1753). Paid him Nces, Llndl. 

 Introd. Njit. Syst. Kd. 3, 450 (183»;). Alhigustavhymn Nces, 

 ♦Stoud. Noni. Ed, 3, 1 : 50 (1840). riotia Schicb. Steud. Nom. 

 Ed. 3, 3:350 (1841). 



Spikelets of modium size, conipressod-keelod, 2-0- (nirely 

 7-10-) llowerod, pcdicelhito in a iniiiiclo usually looso uiul sprojid- 

 iiig, rarely narrow and spikelike, raehilla articulate between tho 

 floral glumes, glabrous or rarely pilulose, flowers ])erl'ect or 

 aomo of tbo upper ones iin})erfect. Empty glumes membran- 

 ous, keeled, acute or obtuse, unawned, persistent, 1-3-nerved, 

 commonly shorter tliau the floral glumes; floral glume mem- 

 branous or herbaceous with a delicate scaricnis nuirgin, usually 

 obtuse and surrounded by a few loose woolly liairs, 5, rarely 

 7, nerved, the nerves usually bending toward eacli other near tho 

 ui)Ox; palea nearly as long as its glume, i)rominently 2-nerved or 

 3-koyled. Stamens 3-3. Styles short, or very short, distinct, stig- 

 mas plumose. Grain ovcid, oblong, or almost linear, comi)ressed, 

 and rarely with a broi/l groove, glaln-ons, included by glume and 

 palea, free or adhering more or less to the palea when mature. 



Theij are about 80 s})ecies, thougli some authors have extended 

 the number to 300. The genus is the most widely diffused over the 

 globe of any in the family, chiefly in temperate and cool regions, 

 reaching the Arctic circle and Alj)ine summits; very few in tho 

 tropics. The gour.s is a very natural one, well distinguished from 

 Fnigrosfis, Panicidaria (Glycerin), and Fei^tucd by tlie lu-rves usu- 

 ally connivaut in the a\)cx of the floral glumes, liy numy authors 

 J'ua is made to include Atropis. 



The species dift'er from Eriitjrostis in their 5-nerved floral 

 glumes, from Panicidaria and F^duca in their glumes keeled from 

 the base; but there are species apparently intermediate between 

 these largo genera. Poa has also been distinguished from Feslura 

 by the obtuse, always unawned glumes, and the non-adherence of 

 the grain to the palea. Several species oi Poa, however, have acute 

 glumes, and in one 6j)ecie3 they bear fine points. There are some 

 Chilian and Australian species and some Asiatic ones where the 

 grain is adherent to the palea, as in Festucaj even in Poa jjratensis 



