Ribs very low and flat. Sheath keeled (fig. 8). 



Avena elatior, L. (P'alse oat grass). Often hairy (see 

 Group X.). Blades thin and dry. Ligule hairy on 

 the back. Margin never upwards rough. 

 Fig. 6. Apex of blade. 

 Fig. 7. Base of blade and hairy ligule. 

 Fig. 8. Transverse section of round, keeled sheath 



(diagram). 



Fig. 9. The ligule, magnified. After Lund. 

 Fig. 10. Section of the blade shewing the keel, and 

 low flat ribs. After Stebler. 



Blades ribless, with median lines. 



Poa bulbosa, L. (Bulbous meadow grass). A thin and 

 narrow-bladed, taper pointed, and long liguled 

 Alpine Poa. 



NOTES ON GROUP II. ' 



Air a. The other Aira species are bristle-bladed. 

 Alpine forms of A. caespitosa have shorter, and 



narrower (almost bristle-like) blades, but in all 



cases the white strips mark the species. 

 Variegated cocksfoot is now very commonly 



cultivated. 

 All the members of the group are long liguled. 



The blades are folded in Aira and Dactylis. 



The sheath is entire in cocksfoot. 



NOTES ON GROUP III. 



Note i. Phleum. The other species of this genus, 

 viz., P. aspetuni) Vill., and .P. arenarium, L., are 

 never bulbous. P. arenarium is distinguished 

 from all the other species by the folded blades \ 



Note 2. Poa. P. Alpina, L., is a very near ally of P. 

 bulbosa. This somewhat bulbous species is 

 thick and broad bladed : the point of the blade 

 is abrupt, not tapered. 



All Poas have ribless, keeled blades, with median 

 lines. P. maritima has no keel. 



