Colorado Plants I> 7 jurious to Live:stock 
19 
J^'igs. 8- 12.—Mechanically injurious grasses: 8, sand-bur; 9, grain of three-awned grass; 
10, grain of porcupine grain showing long, twisted beard; 11, spikelets of downy brome- 
grass; 12, triplet of spikelets of squirrel-tail grass. 
