170 CLASSIFICATION OF [CH. 
(Smm.) terminal awn or a mere tooth. Rounded back. 
Fruit grey-brown, ciliate above, 5—6 x 1-4 x 0°7—0°9 mm., 
depressed, hardly grooved, adhering to the palea. Rachilla 
smooth or not, and narrowed below. 
A noxious weed (see p. 150) and hence should be carefully 
excluded from “seeds.” 
A. caninum, Beauv., has a longer (10mm. or more) 
and rougher awn, and is smaller (about 8 mm.), but 
otherwise very similar. Palea smooth except at the 
five-nerved apex. Rachilla thickened above, and hairy 
(Fig. 75). 
Elymus differs from Agropyrum in its harder velvety palea, no 
awn, and its club-like velvety rachilla. It is also larger altogether, 
as a rule. 
a 
Fig. 77. Brachypodium pinnatum. Type of boat-shaped ‘‘seed” with 
awn. a, nat. size; 6 and c, x7. Nobbe. Cf. Fig. 72. 
