Palea about 3 mm. long with toothed apex and very thin caryopsis 1 mm. A conspicuous tuft of fine silky hairs, longer than the palea at the base and on the rachilla.
Awn slender, dorsal, about as long as the palea.
C. stricta, Nutt. and C. strigosa, Hartm. are rare.
†† Basal hairs shorter than palea.
⊙ Awn brown, bearded in the middle, thickened and white above.
Aira canescens.
The student will find considerable difficulties in the various species of Aira and Agrostis, owing to their small size and variability as regards awn and basal hair-tufts. All these are weeds, but some occur as adulterants.
Aira canescens, L.
"Seed" (apart from the awn, it is very like Agrostis) 1·5-2 mm., with a very thin, smooth, keeled, two-nerved 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.