94 



Fig. 70. Avena fatua Linn. WILD OAT.— o, Empty glumes ; b, a spikelet 

 with the empty glumes removed. Figs. 165 and 166 In Bui. 7 also illustrate 

 the genus Avena. 



70. AVENA Linn. Sp. PI. 79. 1753. Spikelets 2- to 6-flowered; rachilla articu- 

 lated above the empty glumes, bearded below the flowering glumes. Empty 

 glumes 2, unequal, membranaceous, longer than the flowering glumes; flower- 

 ing glumes rounded on the back, 5- to 9-nerved, often bidentate at the apex, 

 with a long, dorsal twisted awn. (The awn may be straight or even absent 

 in cultivated forms). Grain pubescent, at least at the apex, frequently adher- 

 ing to the fruiting glume or palea. Annuals or perennials with rather large 

 spikelets variously paniculate. 



Species about 50, widely spread over the temperate and cooler regions of the 

 world. There are 2 or 3 native North American species, and 2 or 3 others, intro- 

 duced from Europe, exist as weeds in some parts of the country. 



