GEAMINEAE 35 



2. P. fluitans (L. ) Kuntze. Culms flat, large and stout, l°-5° long, 

 erect or decumbent : panicle 1° long with erect or spreading branches : 

 spikelets 7-13-flowered. — Low grounds west of Buokner. May-August. 



49. FESTUCA L. Fescue Grass. 

 Spikelets 2-several-flowered, paniculate or racemose. Two lower 

 glumes empty, keeled. Flowering glUmes 3-nervcd, rounded on the 

 back, acute or awned. Palet a little shorter, usually adhering to the 

 grain ao maturity. 



Flowering glumes awned ; annuals. 1. F. octoftora. 



Flowering glumes not awn.ed ; perennials. 

 Spikelets 4^" or more long. 2. F. elatior. 



Spikelets Z" or less long. 



Spikeletsobovate, crowded at the ends of the branches. 3. F. dbtusa. 

 Spikelets lanceolate, not crowded at the ends of the 



branches. 4. F. nutans, 



1. P. ootoflora Walt. Culms erect, tufted, 4M8'' high : leaves l'-2' 

 long, bristle-form : panicle simple and spike-like, I'-S' long : spikelets 

 flat, oblong, 2Y'-i" long, 6-13-flowered. — Frequent in dry, sandy soil, 

 especially in bottoms along the Missouri Biver. May. 



2. P. elatior L. Meadow Fescue. Culms l°-3° high, erect, gla- 

 brous : leaves numerous, 2'-15' long : panicle simple or compound with 

 short, erect, crowded branches 4'-! 4' long : spikelets 5-8-flowered, i\" or 

 more long : flowering, glumes obscurely 5-nerved, scarious margined, 

 aoutish. — Common in waste places, streets, along railroads, etc. June- 

 August. 



3. P. obtusa Spreng. Spikelets crowded at the ends of the widely 

 spreading branches of the large panicle, ^Y'-y lo"g ■ flowering glumes 

 2" long, obtuse. Otherwise like the next from which, however, it is 

 very different in a.spect. — Woods and prairies. Widely distributed in the 

 southern part, but not common. June-July. 



4. P. nutans Willd. Culms lJ°-3° tall, erect, glabrous or sometimes 

 pubescent : leaves \y-Z" wide, 4'-10' long : panicle very scabrous, 4'- 

 10' long, the branches erect or spreading in age, flower-bearing at the 

 extremities : spikelets 3-5-flowered : flowering glumes 2" long, acute. — 

 Common in rich, rocky woods. May-June. 



50. BROMUS L. Chess. 

 Spikelets borne in terminal panicles, 5-many-flowered. Empty glumes 

 1-3-nerved , acute. Flowering glumes 3-9-nerved, rounded or compressed, 

 keeled on the back, apex mostly 2-cleft, and usually awned below the 

 summit. Grain adhering to the two-keeled palet, which is shorter than 

 the scale. Styles attached below the apex of the ovary. 



Lower empty glume 1-nerved, upper 3-nerved. 1. B. purgana. 



Lower empty glumes 3-nerved, upper 5-9-nerved. 



