160 CLASSIFICATION OF [CH. 
palea, bifid at its apex, through which the yellow caryopsis 
shines. 
Awn slender, basal, dark-brown, with oblique colourless 
hairs above the middle and with a slight swelling above. 
The palea has a few hairs on its mid-rib below. 
Caryopsis about 1 mm. long. 
This grass is somewhat rare in England. The jointed basal awn, 
with a minute hair-tuft above the middle, is unique, and readily 
distinguishes it when mixed with Agrostis. 
@® © Awn not bearded or thickened. 
Ii 
Palea bifid at apex. 
Aira caryophyllea. 
A. precox. 
Aira caryophyllea, L. 
“Seed” 1-4—1°6 mm., comma-shaped and dark-brown. 
Palea acute, nerveless, inrolled at edges and with a 
dorsal, kneed, very fine, dark twisted awn twice as long as 
the palea: the latter with two-toothed apex and a basal 
hair-tuft. 
A common impurity in commercial seed. 
Aira precox, L. is very similar, and cannot be distinguished 
with certainty by the “seed,” but has a shorter awn and no basal 
hairs. Apex of palea two-toothed. 
== Palea jagged or toothed, but not bifid. 
Aira flexuosa. 
A. cespitosa. 
Aira flecuosa, L. (Fig. 70). 
Palea 5mm. long, four-toothed at the apex, and 
caryopsis 2% mm. The fine basal awn waved or kneed, 
about twice as long as the palea. Fruit with a groove. 
