GAMA GRASS. 147 



spike, thick, nodding, six to nine inches long, yellowish 

 or purplish ; bristles two or three in a cluster. Intro- 

 duced from Europe. 



61. CENCHRUS. Bur Grasses. 



Spikelets enclosed, one to five together, in a round- 

 ish and bristly covering, which becomes a hard bur. 



BUR GRASS, or HEDGEHOG GRASS ( Cenchrus tribuloides), 

 is somewhat common on sandy soils on the coast, or 

 near the salt water, where the spikes are whitish, and 

 around the great northern lakes. It is regarded as a 

 troublesome weed, on account of its prickly burs. Stems 

 branched at the base, from one to two feet high ; leaves 

 flat ; spike oblong. 



62. TRTPSACUM. Gama Grass. 



Spikelets in jointed spikes, staminate above, and fer- 

 tile below ; staminate spikelets two, both alike ; two- 

 flowered ; lower glume nerved ; upper boat-shaped ; 

 pales thin, awnless ; anthers opening by two pores at 

 the apex ; sterns tall and large, solid, from thick, creep- 

 ing roots ; leaves broad and flat. 



GAMA GRASS, or SESAME GRASS (Tripsacum dacty- 

 loides), is one of the largest and most beautiful grasses, 

 though not one that would be considered of much value 

 where better could be grown. Its stalk is from four to 

 seven feet high, and the leaves look not very unlike 

 those of Indian corn. Grows on moist soils, near the 

 coast, from New England to Pennsylvania, west to 

 Illinois, and more common at the South, in Louisiana, 

 and adjoining states, where it is indigenous. It is a 

 stout, coarse, and hardy grass. 



63. ERIANTHUS. WooUy Beard. 



Spikelets in pairs on each joint of the slender rachis, 

 one on a pedicel, the other connected at its base, crowded 



