GRAMINEJ3. 49 



Snbtribe II. Euagrostece. Spikelets 1-fld. usually small, 



in open or contracted many-fld. panicles ; gls. usually 



^H thin or membranous ; stigmas laterally exserted from 



the spikelet. (Spikelets rarely 2-fld. in Sporobolus 



and MuehletibergicL). 



Spikelets articulate on their pedicels, or gl. I and 



II separately deciduous, or pedicel articulate in the 



middle. 48. Polypogon. 



Spikelets and pedicels inarticulate, gl. I and II 



persistent. 



Gls. all awnless ; I and II 1 -nerved, pericarp 

 of grain loose. 49. Sporobolus. 



Gls. I and II subequal, 1-nerved, awnless, 

 awn of III dorsal or 0. 50. Agrostis. 



Gls. I and II unequal, awuless, 1-nerved, awn 

 of III terminal. 51. Muehleribergia. 



Gls. I and II 3-nerved, awnless, base of 

 III penicillate with long hairs. 



52. Calamagrostis. 



TRIBE VI. AVENE^E. Spikelets 2- or more flcl., panicled, very 

 rarely spicate, or panicle subspiciform ; fl. gls. 

 usually avvned, awn geniculate and often twisted, 

 rarely straight or ; rachilla produced or not beyond 

 the upper fl. gl. 



Subtribe I. Airece. Spikelets 2-fld.; gls. membranous ; 

 rhachilla not produced. 53. Aira. 



Subtribe II. Euavenece Spikelets 2- or more fld., rhachilla 

 produced. 



Spikelets 2-fld., both bisexual, awned. 



54. Descliampsia. 



Spikelets 2-6-fld.; fl. gl. awned, awn subterminal 

 or dorsal 



Annual. Spikelets pendulous ; gl. I and II 5-7- 



