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SUBTRIBE 1.— STIPES. 



Spikelets paniculate. Rhachis not produced beyond the flower ; 

 beard of the flowering glume terminal. 

 Genera: 1. Aristida ; 2. Stipa; 3. Oryzopsis; 4. Milium; 5. 

 Muhlenbergia ; 6. Braohyelytrum. 



Subteibe 2.— PHLEOIDE^. 



Spikelets in a dense spike-like or ovoid panicle. Rhachis produced 

 beyond the flower in a bristle, or naked. Flowering glumes 

 awnless, or produced in one to three straight bristles. 

 Genera: 1. Lycnrus ; 2. Heleochloa; 3. Phleum. 



Subteibe 3.— SPOROBOLEiE. 



Spikelets usually small, loosely spicate or variously paniculate. Rha- 

 chis not produced beyond the flower ; glumes unawned, or 

 the flowering glume rarely produced in a short straight 

 beard. 

 Genera: 1. Coleanthus; 2. Phippsia; 3. Sporobolus. 



Subteibe 4.— EUAGBOSTE^. 



Spikelets generally small ; variously paniculate. Flowering glume 



usually with a more or less twisted dorsal awn ; rarely 



mucronate or awnless. 

 Group I. — Rhachilla not produced beyond the flower. 



Genera: 1. Epicampes ; 2. Agrostis; 3. Polypogon ; 4. 



Arctagrostis ; 5. Cinna. 

 Group 2. — Rhachilla produced beyond the flower in a bristle which 



may be glabrous or most frequently hairy. 

 Genera : 1 . Gastridium ; 2. Apera ; 3. Deyeuxia ; 4. Ammo- 



phila. 



Tribe 3.— AVENE^E. 



Spikelets two-flowered, rarely many-flowered, often paniculate. 

 Flowering glumes usually provided with a dorsal or sometimes a 

 terminal awn, or awnless in some equally two-flowered genera. 



Subtribe AIRE^. 

 Spikelets two-flowered, paniculate or rarely spicate ; not produced 



