28 GEAMINEAE 



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

 tracted or with widely spreading branches : spikelets 9" long, 2-flowered, 

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

 ers : perfect flower long-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 1-flowered. 

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

 the flower. Palet often larger than the glume. 



1. S. cynosuroides ( L. ) Willd. Maesh-geass. 3°-6° high : leaves 

 involute, pointed, 1° or more long : spikes 5-25, 2'-5' long, short-pedan- 

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

 cated, 6"-'!" long: outer glumes awn-pointed. — On wet prairies through- 

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

 October. 



31. SCHBDONNARDUS Steud. 



A decumbent annual with short leaves, 1-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, \'-i' 

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

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

 July. 



32. BOUTBLOITA Lag. Mesquitb Geass. 



Eachilla 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. 1. B. oligostachya. 



Spikelets twenty to sixty. 2. B. curtipendula. 



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

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

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

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



2. B. curtipendula (Michx.) Torr. Culms 2°-3° high : leaves 7'-10' 

 long, tapering to a long slender point : spikes 3"-8" long, spreading or 

 reflexed. — 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 saccate, the flow- 

 ering glumes narrower and lanceolate. Palet hyaline. 



