(12) 



2. Agrostis. Glumas acute, the inferior 

 one larger. Paleas merabranaceous. 



3. Calamagrostis. Glumes acute, the in- 

 ferior one larger. Pale* surrounded by 

 silky hair at the base. 



4. Stipa. Glumae acute, sometimes aris- 

 tate. Paleae cartilaginous, the inferior 

 one cylindrically involute. Awn strong, 

 articulate at the base, persistent, de- 

 veloped from the apex of the palea. 



6. Gastridium. Glumse acute, very much 

 compressed, ventricose at their base. 

 Palese membranaceous. 



d. Spikelets pedicillate, 2- ^-flowered, the 

 uppermost floret frequently rudimentary. 



aa. Stigma aspergittiform, exserted below the 

 apex of the floret. 



1. Phragmites. S pikelets oo-flowered, 

 lowermost floret 3 or neuter, the other 

 florets and pilose. 



2. Hierochloa. Spikelets 3-flowered, the 

 two inferior ones $ and triandrous, the 

 terminal one and diandrous. 



bb. Stigma plumose, exserted near the base of 

 the floret. 



1. Arrhenatherum. Spikelets 2-flowered; 

 inferior floret $ , aristate ; superior 

 floret $ , awnless. 



