54 



NOTES ON GROUP VI. 



1. Reed grasses. The largest are : Glyceria aquatica, 

 Phalaris arundinacea, and Phragmites communis. 



Flat sheathed Glyceria aquatica. 

 Round sheathed : 



Long liguled Phalaris arundinacea. 



Ligule a hair tuft Phragmites communis. 

 The small reed grasses are : Molinia and Cala- 

 magrostis. 



Ligule a long membrane Calamagrostis. 



Ligule a hair tuft Molinia. 



2. An aquatic not included in this group is 

 Alopecurus geniculatus. It is distinguished by the 

 very high (about twice as high as broad) and very 

 acute ribs. 



