156 CLASSIFICATION OF [CH. 



Alopecurus pratensis, L. (Fig. 68). 



Inner palea absent. Outer palea 5 mm., caryopsis 

 3 mm. long, often with remains of the stigma. 



The greyish-brown spikelet of Alopecurus easily falls 

 as a whole, included in the glumes ; the palea is loose and 

 delicate. 



Glumes connate below, silky-hairy on keel and ribs all 

 the way up. The palea has a bent dorsal awn, about 5 mm. 

 long. 



Alopecurus geniculatus, L. 



Palea 2 mm., fruit 1'3 mm. long. 



The glumes hairy on ribs and keel as in A . pratensis : 

 glumes more obtuse. 



Alopecurus agrestis, L. 



Palea 6 mm., fruit 3 mm. long. 



Glumes only ciliate, on ribs and keel, except at the 

 base where the hairs are longer. 



Keel slightly winged. 



Best distinguished from A. pratensis by the glumes, which are 

 smoother, broader above the middle, harder and with a few basal 

 hairs. 



The species A.fvlvus, A. hvlbosus, and A. alpinus are rare. 



(ii) "Seed" consisting of the palese investing the 

 caryopsis, freed from the glumes. 

 * Palea at least 14 or 15 otto, long: caryopsis 

 5 — 7 mm. [Oat type.] 

 Avena f atria. 

 A. pratensis. 



Avena fatua, L. 



Palea parchment-like, lanceolate-terete, acuminate and 

 bifid at the apex, rounded on the back and with yellow 



