THE GRASSES OF MAINE. 15 



f Outer glumes much shorter than the flowering glume, 

 , 9 J Sporobolus. 



- ] Outer glumes about the same length as the flowering glume, 

 L Agrostis and Sporobolus. 



1 o f Flowers with awns 14 



\ Flowers without awns 20 



-m f Spikes solitary 15 



{ Spikes two or more Andropogon. 



, - f Spikes simple or nearlj- so 16 



| Spikes paniculate or lobed 18 



\ Inv 



Mn /olucre of two or more bristles Setaria. 



Involucre none 17 



( Flowering glumes with awns from one to three times their 



length Alopecurus. 



| Flowering glumes with awns five times their length. 



Hordeum. 



i Flowers without awns Hierochloa. 



Flowers with awns 19 



i Only the flowering glumes awned Muhlexbergia. 



Flowering glume and palea both awned Anthoxanthum. 



{ 



20 jSpj* 

 ( Spik 



es terminal, cylindrical and solitary Phleum. 



kes one-sided, several Spartina. 



Flowers arranged in panicles 22 



Flowers arranged in spikes 33 



aa f Flowers with awns 23 



\ Flowers without awns 28 



o« f Flowering glume awned on the back 24 



"° \ Flowering glume awned from the end 27 



( Awn arises near the base of the flowering glume Aira. 



24 -j Awn arises above the middle of the back of the flowering 



( glume .... 25 



25Jf wu 



( Awn 



arises near the middle and twisted Trisetum. 



arises at or near the apex, not twisted 26 



•?6 f Spikelet8 from three to six flowered (Plate 29) Avena. 



j Spikclets from five to twelve flowered (Plate 22). . .Bromus. 



f Awn twisted and arising from a cleft at the end of the flow- 



I ering glume Damhomv. 



1 Awn not twisted, arising from the end which is not cleft, 

 I Festuca. 



