Ix] “ SEEDS ” 159 
much grooved, fusiform, 2—3 mm. long, glumes unequal, 
somewhat keeled and rough. 
(2) Awn dorsal or basal, fine and hair-like, and 
little or not at all twisted or kneed. “Seed” 
small. 
* A pencil of silky hairs on base or rachilla. Palea 
bifid at the tip. 
t+ Basal hairs longer than palea, and obscuring the 
awn. 
Calamagrostis Epigeios. 
Of little importance. Digraphis has no awn. 
Calamagrostis EHpigeios, Roth. 
Palea about 3mm. long with toothed apex and very 
thin caryopsis 1mm. 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. 
+t Basal hairs shorter than palea. 
© <Awn brown, bearded in the middle, thickened 
and white above. 
Avra 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. 
Avra canescens, L. 
“Seed” (apart from the awn, it is very like Agrostis) 
15—2 mm., with a very thin, smooth, keeled, two-nerved 
