38 Aveneae 



Tribe 5. AVENEAE. Oat Tribe. 



Spikelets 2 — everal-flowered ; outer empty glumes 

 usually longer than the first flowering glume : 1 or more 

 of the flowering glumes awned on the back or from be- 

 tween the teeth of the bifid apex: awn usually twisted 

 or geniculate. 



Spikelets articulated with the pedicels below the empty glumes. 



19. Holcus. 

 Spikelets not articulate below the empty glumes. 

 Au lis dorsal. 



Spikelets small, less than 1 cm. long. SO, DESCHAMPSIA. 



Spikelets 1 cm. long or more. 21. A VENA. 



Awns terminal, rising from between the lobes or teeth. 



22. DANTHONIA, 



19. HOLCUS L. Velvet-grass. 



Annual or perennial grasses with tlat Leaves and spike- 

 like or open panicles. Spikelets deciduous, 2-flowered ; 

 lower flowers perfect, upper staminate. Glumes I: the 

 2 Lower empty, membranous, keeled, the firsl t-nerved, 

 the second 3-nerved and often shorl awned : flowering 

 glumes chartaceous, the upper ones bearing a bent awn. 

 Palea narrow. 2-keeled. Stamens .">. Styles distinct. 

 Grain oblong, enclosed in the glume. 



1. H. lanatus L. Densely and softly pubescent throughout; 

 culms 4-6 dm. high, erect, often decumbent at the base, simple; 

 sheaths shorter than the internodes; ligule 1-2 mm. long; leaves 

 3-8 cm. long, 4-10 mm. wide; spikelets 4 mm. long; empty 

 glumes white-vilious, the upper awn-pointed; flowering glumes 

 2 mm. long, smooth and shining, the lower sparsely ciliate on the 

 keel, somewhat obtuse, the upper 2-toothed and bearing a hooked 

 awn below the apex. 



Santa Anita and Oak Km ill, McClatehit , DdVic 



20. DESCHAMPSIA beam. 1 1 aih-ciiass. 



Annual oi perennial grasses with flat or convolute 

 leave- and contracted or "pen panicles. Spikelets 2- 



