Key to the Grasses 



PAGE 



Spike 3'-io' long, coarse; spikelets several-flowered, in 2's or 3's on 

 alternate notches of the rachis; empty scales conspicuous. 



Terrell Grass .... 248 

 Slender Wild Rye . . . 247 

 Nodding Wild Rye . . 247 

 Spike 3'-7' long; spikelets 2-4-flowered, usually in pairs; empty scales 

 minute or awn-like, flowering scales long-awned. 



Bottle-brush Grass . . . 250 

 Spike-like panicle i'-^' long; spikelets i-flowered, narrow; scales 

 5; 3d and 4th scales short-awned. 



Sweet Vernal-grass ... 97 

 Spike-like panicle 2'-i8'long; spikelets i -flowered, narrow; flower- 

 ing scale bearing 3 awns. Poverty Grass . . . . 102 



Slender Aristida. . . . 105 

 Purplish Aristida . . . 105 

 Spike-like panicle 5'-i2' long, cylindrical, densely flowered; spike- 

 lets long and narrow; scales not awned. A grass of sands and 

 sea beaches. JVlarram Grass . . . 128 



Spike-like panicle 8'-i 5' long, composed of numerous, short, spread- 



ingordownward-pointing spikes. Tall Grama . . . 164 



Spike-like panicle 4'-i2' long; spikelets short, several-flowered; 



empty scales minute. Slender Spike-grass . . . 183 



Spike-like panicle r-25' long; spikelets many-flowered. Staminate 

 and pistillate flowers on separate plants. 



Marsh Spike-grass . . . 187 

 Spike-like panicle 2'-4' long, rough; spikelets of two forms in numer- 

 ous clusters. Dog's-tail Grass ... 195 



II. — INFLORESCENCE CONSISTING OF SHORT PANICLES, ONE TO FOUR 

 INCHES IN LENGTH. 



Panicle pyramidal; spikelets roundish, only i fertile flower in each 



spikelet; scales 4. Scribner's Panic-grass 74 



Starved Panic-grass 71 



Round-fruited Panic-grass ... 71 



Panicle pyramidal; spikelets 3-flowered; scales 5. 



Vanilla Grass ... 98 

 Panicle pyramidal; spikelets 2-flowered, small; scales 4. 



Silvery Hair-grass . . . 132 

 Panicle pyramidal, often i-sided; spikelets 3-6-flowered, small; 

 flowering scales with short hairs at the base. 



Low Spear-grass . . . 205 

 Canada Blue-grass . . . 197 

 Panicle not many-flowered; spikelets loosely 2-5-flowered; flower- 

 ing scales hairy on nerves, minutely awned. 



Sand-grass . . . 172 



41 



