90 AVENEAE 



Tribe VI. AVENEAE. Oats Grasses. 



Awns of the flowering Klumes attached on the 

 back below the teeth of the glume. 

 Grain free, unfurrowed; spikelets less than 1-2 

 an inch long. 

 Flowering glumes erose-toothed or 



shortly 2-lobed at the apex. ;iS. Deschampsia- 



Flowering glumes deeply 2-toothed at the 

 apex, the teeth awn-pointed; awn bent 

 and twisted. zo. Trisetum. 



Grain adherent, furrowed to the glumes; 

 spikelets nsostly more than 1-2 an inch 

 long; ovary crowned with a hairy ap- 

 pendage. 40. AVENA. 

 Awns of the flowering glumes attached be- 

 tween the teeth of the glume. 41. Danthonia. 



38. DESCHAMPSIA Biauv. Hair Grass. 



Plant low, 8-16 inches high; empty glumes 4 



mm. long: awn much longer than the 



flowering glume. \. 1). alpicola. 



Plant taller, 2-3 feet high; empty glumes 3-3.5 



mm. long: awn little if any longer than the 



flowering glume. 2. D. cuespitosa. 



1. Deschampsia alpicola Kydb. On the top.s of the high 

 peaks in the noi'lhcrn paH of tlie State, in the Arctic-alpine Zone. 



2. Deschampsia caespitosa (L.) Beauv. in the higher 

 mountains of the State in the Transition and Canadian Zones. 



39. TRISETUM Pers. False Oats. 



Panicle slender, interruiited; plant slender. 1. T. intcrruptum. 



Panicle dense and crowded, more or less 

 branched but not spreading: plants stouter. 

 Leaf sheaths and blades long hairy; upper 



part of the stem densely pubescent. .?. T. snbsi)katu)n. 



Leaf sheaths and blades glabrous or the lo.w- 

 est sheath short pubescent with reflexefl 

 hairs: stem glabrous or slightly scabrous 

 in the inflorescence. 3. T. niontanum Vasey. 



1. Trisetum interruptum I'.uckl. Known in New Mexico 

 from a single collection in the southern ptirt of the State in the 

 Upper Sonoran Zone. 



2. Trisetum SUbspicatum (I..) Beauv. In the mountains of 

 the northern part of the State in the Canadian Zone extending up 

 into the Hudsonian Zone. 



