40 Botanical Section [PT i 



of the central spikelet not fringed, the palese of 



the central spikelet not enclosing a grain (rare). 



(b) Awn not exceeding twice the length of the O.P. 



H. pratense, glumes all bristle-like, not dilated 



(p. 111). 

 H. maritimum, inner glume of lateral spikelets 



dilated on one side. 

 2. "Seed" consisting of only the I. P. and O.P. enclosing 



the "grain." 

 (a) " Seed " somewhat flattened or compressed ; barge 



or boat-shaped. 

 (x) Awn from | to f the length of O.P., which 



is 5-7 mm. long. 

 Lolium italicum (p. 115), rachilla rather 



flattened and smooth (Fig. 124). 

 L. woldicum, rachilla rather flattened 



and smooth (p. 156). 

 Bromus giganteus, rachilla cylindrical, 

 usually rough with short bristly hairs 

 (Fig. 80) (p. 85). 



(y) Awn from | to j the length of O.P., which 

 is 9-12 mm. long ; rachilla cylindrical 

 and usually hairy. 



^Agropyrum caninum,\)a,ck of O.P. smooth 



and without a distinct keel (Fig. 30). 



Bromus erectus (Fig. 75), back of O.P. 



scabrid or hairy and with a distinct 



keel (p. 84). 



Brachypodium sylvaticum, back of O.P. 

 hairy but without a distinct keel (Fig. 

 63) (p. 74). 



(z) Awn-point half the length of the O.P. or 

 less; O.P. 7-12 mm. long; rachilla 

 round, smooth or pubescent. 

 Brachypodium pinnatum (Fig. 64), O.P. 

 nerved above but without a distinct 

 keel (p. 76). 



1 In Agropyrum the awn is sometimes slightly sub-terminal. 



