polypogon GRAMINEift 725 



.AGKOSTIS 



leaves flat, 2-6 inches long, 1-3 lines wide, somewhat scabroits : panicle 2-6 

 inches long cylindric or somewhat interrupted, yellowish, dense and soft : 

 empty glumes about 1 line long, obtuse, notched at the apex, bearing slen- 

 der awns 2-3 lines lonyr; flowering glume much shorter, erose-truncate, 

 bearing a slender awn about ^ line long inserted below the tip. Common 

 in wet places, Brit. Columbia to Mexico and the Atlantic States. 



P. littoralis Smith Comp. Fl. Brit. ed. 2, 13. Stems slender, from a 



f>erennial root, 1-2 feet long, often decumbent and forming large tufts: 

 igules 1-3 lines long, acute: leaves narrow, scabrous on both sides: pani- 

 cle narrow, much lobed its whole length and sometimes completely inter- 

 rupted below, often purplish : empty glumes scabrous, attenuate above into 

 an awn as long as the body: flowering glume much shorter than the empty 

 ones, obtuse, 2-toothed at the apex : awn 1 line long. In wet places, Ore- 

 gon to California: also in Europe and South America. 



12 AGROSTIS L. Sp. 6. 

 Annual or perennial grasses with flat or involute leaves and 

 numerous flowers in more or less open panicles with whorled or 

 clustered branches. Spikelets small, one-flowered or sometimes 

 with the rudiments of a second flower. Empty glumes somewhat 

 unequal, the lower usually longest, obtuse or acute, membranous. 

 Flowers mostly shorter than the empty glumes, with a very short 

 naked base. Flowering glume very thin, 3-5-nerved, pointless, 

 naked, often bearing a slender straight awn on the back usually 

 much below the apex. Palet obsolete, or present and shorter 

 than or equalling the ovary, rarely nearly as long as the glume. 

 Stamens mostly 3. Styles 2 distinct, short, with plumose stigmas. 



A. equivalvis Trin. Agrost. ii, 116. Stems slender, erect, 1-2 feet 

 high, smooth : sheaths smooth, shorter than the internodes: upper ligules 

 about 1 line long: leaves flat, 4-6 inches long, smooth or nearly so: panicle 

 2-6 inches long, loose, very narrow, smooth and shining, the branches in 

 whorls of 5 below, in pairs or solitary above, very unequal : spikelets 1-1 ^ 

 lines long, mostly in pairs: empty glumes nearly equal, acute, 1-1}^ lines 

 lpng: flowering glume acute. 5-nerved : palet about as long as the glume. 

 In moist ground, Alaska to California. 



A, alba L. Sp. 63. (Redtop.) Stems slender, erect, often decumbent 

 at base, 6-30 inches high: sheaths smooth: ligules short and truncate or 

 long and acute: leaves flat, 4-12 inches long, smooth or rough: panicle 

 slender, 2-8 inches long; green, red or brownish, its roughish branches 

 usually spreading in flower and more or less contracted afterwards: empty 

 glumes nearly equal, or the lower slightly longest : flowering glume very 

 thin, with some short hairs at base, shorter than the empty ones, rarely 

 with a short awn : palet %-% as long as the glume. Common in meadows 

 and waste places. 



A. exarata Trin. Unifl. 207. Stems 1-3 feet high, erect, sometimes 

 decumbent at base, simple, glabrous: sheaths usually shorter than the 

 internodes: ligules 1-3 lines long: leaves 1-8 inches long, 1-4 lines wide, 

 generally erect, flat or involute, scabrous : panicle contracted, 2-10 inches 

 long, often interrupted, its branches 1-3 inches long, erect or appressed : 

 spikelets crowded, 1-2 lines long: empty glumes subequal, scabrous: flow- 

 ering glume %-% li ne long: palet minute. In moist meadows and along 

 streams, Alaska to California and Nebraska. 



A, asperifolia Trin. Mem. Acad. St. Petersb. ser. 6. 331. Pale green 

 th roughout or the inflorescence purplish : stems erect or slightly geniculate 

 below, nearly smooth, 2-3 feet high: sheaths rather loose, smooth, the 



