( 304 ) 
Ovary sessile, hirsute at the apex; caryopsis 
terete, adherent to the upper palet.—©. 
1. A. Fatua .—Common. Summer. 
1%, Trisetum Kunth. 
Spikelets 2-4-flowered, the uppermost depau- 
perate. Glumes 2, carinate, awnless, shorter 
than the flower. Palets 2; lower 2-dentate, 
aristate. Ovary sessile; caryopsis compressed, 
free. Leaves flattened. , 
1. T. canescens Buckl. Spikelets 2 or 3- 
flowered, narrow; lower glume narrow, con- 
siderably shorter than the broad ovate upper 
one.—@®. Common. Spring. 
2. T. BarBaTuM Steud. Spikelets 3-5-flow- 
ered, laree, much flattened; both glumes nar- 
row, the lower but little shorter than the up- 
per one.—©. Common. Spring. 
18. Aira L. Hatrr-GRAss. 
Spikelets 2-flowered, often with the rudiment 
of asuperior one. Flowers sessile. Glumes 2, 
carinate, awnless, larger than the flower. Palets 
2; the lower 2-cleft, dorsally aristate. Ovary 
sessile; caryopsis free. 
1. A. cmsprrosa L. Glumes not longer than 
the florets ; spikelets much compressed.—?2f. 
San Francisco. Summer. 
2. <A. HOLCIFoRMIS Steud. Glumes not longer 
than the florets ; spikelets nearly terete.—2. 
Common. Summer. 
