95 



Fig. 71. Arrhenatherum elatius (L.) Beauv. {Avena elatior L.) . TALL OAT- 

 GRASS.— a, A spikelet; b, the same with the empty glumes removed. The first 

 floret is long-awned, while the second floret is short-awned or nearly awnless. 



71. AEKHENATHEETJM Beauv. Agrost. 55. 1812. Spikelets 2-flowered, the 

 first or lower flower staminate, its glume bearing a twisted and geniculate awn 

 on the hack near the base; the upper flower hermaphrodite, its glume short- 

 awned from or near the tip, or awnless; rachilla hairy, articulated above the 

 empty glumes, and extending into a short point or bristle behind the palea of 

 the upper flower. Empty glumes unequal, acute, their margins thin and scari- 

 ous. Flowering glumes firmer in texture than the empty ones, 5-to 7-nerved, 

 closely approximate. Palea prominently 2-nerved. Stigmas sessile. Usually 

 tall perennials, with flat leaves and long, narrow panicles. 



Species 5 or 6, in the Old World. One introduced and naturalized in the 

 United States. 



