28 GRAMINEA1-: 



1. A. sativa L. Oats. Annual, 2°-4° hifi:h : leaves flat : panicle con- 

 tracted or with widely spreading branches : spikelets 9" long, 'J-flowcred, 

 the two empty glumes acute, scarious at apex and longer than the flow- 

 ers : perfect flower loug-awned or awnless. — Frequent in waste places, 

 and often very abundant along railroads. May-October. 



30. SPARTINA Schreb. 



Tall perennials from long creeping rootstocks. Spikelets l-flowered. 

 Glumes three, the two outer empty and unequal, the third subtending 

 the flower. Palet often larger than the glume. 



1. S. cynosuroides i L. ) Willd. Marsh-grass. 3°-6° high : leaves 

 involute, pointed, 1^ or more long : spikes 5-25, 2^-5^ long, short-ped un- 

 cled : rachis and glumes rough on the margins : spikelets closely imbri- 

 cated, ^''-l" long: outer glumes awn-pointed. — On wet prairies through- 

 out the county, but especially abundant from Adams to Levasy. July- 

 October. 



31. SCHEDONNARDUS Steud. 



A decumbent annual with short leaves, l-flowered spikelets, sessile 

 and appressed, in spikes. Glumes three, the two outer empty, acumi- 

 nate and keeled, the third somewhat longer, but similar. None awned. 



1. S. paniculatus ( Nutt. ) Trelease. l°-2° high : inflorescence scab- 

 rous, taking up three-fourths of the plant : spikes 6-10, distant, V-\' 

 long, widely spreading. — Locally common in barrens at Dodson and 

 Little Blue Tank ; also occasionally adveutized along railroads. June- 

 July. 



32. BOUTELOUA Lag. Mesquite Grass. 



Kachilla produced beyond the flower, bearing awns and scales Lower 

 glumes keeled. Flowering glume three-toothed and awned or pointed. 

 Palet 2-nerved and 2-toothed. 



Spikelets one to four. ■[. B. oligostachya. 



Spikelets twenty to sixty. 2. B. vurtipendula . 



1. B. oligostachya (Nutt.) Torr. Culms about 1° high : leaves 3'- 

 4^ long, with a long slender tip : spikes usually two, about 1' long, 

 curved, oblong-linear, many-flowered, short-peduncled— Sparingly ad- 

 ventized along railroads, especially at Sheflield. June-August. 



2. B. curtipendula (Michx.) Torr. Culms 2°-3° high : leaves I'-W 

 long, tJipering to a long slender point : spikes y'-W long, spreading or 

 rellexed. — Common in rocky barrens in the .southern part. August-Oc- 

 tober. 



34. BECKMANNIA Host. 



Tall grasses with 1-2-flowered spikelets, borne in close spikes in narrow 

 terminal panicles. Glumes three or four, the two lower sjiccate, the flow- 

 ering glumes nanower and lanceolate. Palet hyaline. 



