1S6 GRASSES OF IOWA. 



Spikelets 2 to many-flowered, panicled ; the flowers herbaceo-char- 

 taceous or becoming harder, of firmer texture than the large and mostly 

 unequal, empty glumes ; the uppermost flower imperfect ; rachis and base 

 of the flower often bearded. Flowering glume rounded on the back, 

 mostly 5 to u-nerved, bearing a long, usually bent or twisted awn on 

 the back between the two acute teeth at the apex, proceeding from 

 the mid-nerve only. Stamens 3. Grain oblong-linear, grooved, on one 

 side, usually hairy, at least at the top, free, but invested by the palet. 

 (The classical Latin name.) 



Species 40 (Bentham <Sc Hooker) ; 50 (Hackel) ; by some the number 

 has been reduced to 30. Mostly in temperate regions of the Old World 

 and sparingly in the New World. United States is credited with two 

 or three naturalized, and eight native species. One species, the A. fatua, 

 is widely naturalized on the Pacific Coast, Rocky Mountains and spar- 

 ingly on the Atlantic Coast, Wisconsin, Minnesota and northeastern 

 Iowa. 



KEY TO THE SPECIES OF AVENA. 



Flowering glume glabrous or hairy at the base only, cultivated 



— .A. sativa. x . 

 Flowering glume hairy to or beyond the middle A . fatua *°- . 



1. AVENA SATIVA. 



Avena sativa L. Sp. PI. 79. 1753. Scribner. Grasses of Tenn. Bull. 

 Univ. Tenn. Agrl. Exp. Sta. 7: 83./. no. 1894. Beal. Grasses of N. A. 2: 

 385. 1896. 



•Flowering glume less hairy than A. fatua, softly pilose. 



