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COHPAEATIVE ANALYSIS. 



Buceiuji. — Inflorescence racemed, approaching to a spike Loliaceum. 



Inflorescence panieled . . -1 



1. Panicle simple .... Pratense. 

 Panicle compound . . . .2 



2. Awn considerably shorter than palea . . Elatius. 

 Awn considerably longer than palea . . Giganteum. 



Beomus. — Large glume seven-ribbed . . . 1 



Large glume three-ribbed . . .4 



1. Summit of upper glume midway between its base and 



summit of third floret . . . .2 

 Summit of upper glume midway between its base and 



summit of second floret . . . .3 



2. Florets and glumes hairy . . . Mollis. 

 Florets and glumes not hairy . . Bacemosus. 



3. Twice width of outer palea considerably more than 



length of palea . . . Secalinus. 



Twice width of outer palea equal to length of palea Arvensis. 



4. Awns of florets much longer than calyx . . 5 

 Awns of florets much shorter than calyx . . 6 



5. Spikelets drooping, awns longer than the florets . Sterilis. 

 Spikelets erect, awns equal in length to the florets Diandrus. 



6. Lower floret about one third longer than the small glume Erectus. 

 Lower floret about twice the length of the small glume Asper. 



Trisetum. — Radical leaves hairy . . .1 



Radical leaves not hairy . . . Pratense. 



1. Ligule long and acute . . . Pulescens. 



Ligule very short and obtuse . . . Flavescens. 



Pesttjca. — Awns much longer than the florets . Bromoides. 



Awns much shorter than the florets . 1 



1. Root fibrous, stem under the panicle rough . . Ovina. 



Root creeping, stem under the panicle smooth . Duriuscula. 



Triticuh. — Spikelets long, on short footstalks . Sijlvaticum. 



Spikelets short, without footstalks . . 1 



1. Stem rough .... Cristatum. 

 Stem smooth .... 2 



2. Awns rather longer than the florets . . Caninum. 

 Awns very short, or wanting ... 3 



3. Rachis rough ..... Bepens. 

 Rachis smooth .... Junceum. 



Lolium. — Florets awned, glume longer than the spikelet Temulentum. 



Florets not awned, glume shorter than the spikelet - Perenne. 



