108 CLASSIFICATION ACCORDING TO [CH. 



has a conspicuously notched rachis and the spikelets arranged in the 

 other plane. 



Poa loUacea, Huds., an uncommon sea-shore weed, may also be 

 placed here; as also Festvx^a elatior, var. loliacea, Curt, and some 

 forms of Sromtis arvensis, var. mollis, L. 



No other British grasses resemble Brachypodium : any superficial 

 likeness remarked in species of Hordeum, Festuca, &c. disappears 

 at once on examination. 



(b) Spike compound — i.e. with clusters of two or 

 more sessile or sub-sessile spikelets arranged 

 along the rachis. 



(i) Spike elongated, fertile spikelets with 3 — 5 flowers. 



* Pasture-grass vdth wiry rachis, on which the spikelets 

 are secund and sessile in clusters: in each cluster a 

 comb-like group of ban-en glumes subtends one of 

 fertile spikelets. 



Cynosurus cristatus, L. 



The rare C. echinatus has the pectinate groups of barren glumes 

 even more prominent. 



** Stout glaucous sand-binder with pairs of spikelets 

 sessile in the notches of the rachis, and all fertile. 

 Spike cylindrical. Not common. 



Elymus arenarius, L. 



For other sand-binders see p. 102. The only grass likely to be 

 confounded is Agropyrum, in which the spikelets are not paired. 

 Lolium, Brachypodium, &c. are easily distinguished. 



(ii) Spike short and ovoid: spikelets sub-sessile and im- 

 bricate, in clusters. Bluish. 



Sesleria ccerulea, Ard. 



Not easily mistaken for any other grass. As some of the 

 spikelets are shortly stalked, the inflorescence is strictly pani- 

 culate, but the fact is not obvious. The gliame-like bract at 

 the base of the spike, and the general appearance suggest resem- 



