158 



CLASSIFICATION OF 



[CH. 



ft Caryopsis not more than 3 mm. long. A hift 

 of hairs on rachilla and base. 



Avena flavescens. 



Aira Jlexuosa, distinguished by its nearly basal awn, harder 

 texture and darker colour of palese, and Dactylis — awnless and with 

 cui'ved long drawn-out. apex — are found as impurities in foreign 

 "seed." 



Fig. 69. Avena flavescens. c, "seed," nat. size; a and h, ditto, x about 



7. The dorsal twisted and kneed awn is very characteristic. Note 



also the hairy rachilla. The palea is bifid above— not visible in the 

 lateral view. Nobbe. 



Avena flavescens, L. (Fig. 69). 



Yellow. Palea about 5 mm. long, five-ribbed, bifid 

 at the apex into two long slender teeth, closely investing 

 the brownish caryopsis, and with a sub-dorsal awn 10 mm. 

 long with little or no twist, and hairy at the base. 

 Rachilla fiattened and with white hairs. Caryopsis not 



