14 



Rhachis of the spikelet with long hairs enveloping the 

 flowering glumes. Lowest flower male. 



Panicle large and loose ... ... ... 85. Phragmites. 



Rhachis of the spikelet glabrous. Spikelets dioecious, 

 few with closely imbricate glumes. Pericarp 

 thick and spongy ... ... ... ... 86. Distichlis. 



Rhachis of the spikelet glabrous or shortly or loosely 

 hairy. Spikelets bisexual. 



Grain free from the palea (except in a few Poae). 



Spikelets usually flat ; the flowering glumes 

 keeled, entire. 



Flowering glume and palea thinly 

 scarious or hyaline, the glume 

 acute or shortly awned, the palea 

 keels broadly winged. 



Spikelets in globular clusters in a 



long interrupted spike ... 87. Elytrophorus. 



Flowering glume membranous or 

 herbaceous, three or five nerved. 

 Spikelets usually many-flowered. 



Flowering glumes three-nerved. 91. Eragrostis. 



Spikelets few flowered. Flower- 

 glumes five-nerved ... ... 92. Poa. 



Spikelets flattened, flowering glume with 

 hyaline tips, notched or two-lobed, the 

 keel forming a small point between the 

 lobes or just below them ... ... 93. Schedonorus. 



Spikelets narrow. Flowering glumes rounded 

 on the back with three or more nerves 

 not reaching to the obtuse hyaline apex 94. Glyceria. 



Grain adnate to the palea when ripe. 



Ovary pubescent, obtuse. Flowering glumes 

 with a dorsal point or awn below the 

 entire or notched hyaline tip ... ... 96. Bromus. 



Ovary glabrous. Spikelets usually narrow. 

 Flowering glumes entire, acute or 

 awned ... ... ... 98. Festuca. 



Subtribe V. — Hordeaceae. — Spikelets one or several flowered, sessile on 

 the opposite sides or alternate notches of the rhachis of a simple spike. 

 Glumes entire, awned or unawned. 



Spikelets several-flowered, flat, one side or face of the 

 spikelet next to the continuous scarcely 

 notched rhachis ... ... ... ... 99. Agropyrum. 



Spikelets one or two flowered, with the rhachis pro- 

 duced above the flower, half embedded in 

 the notches of the more or less articulate 

 rhachis ... ... ... ... 102. Lepturus. 



