250 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE. 
The two species are Amphicarpon purshii Kunth {A. amphicarpon 
(Pursh) Nash), an annual (fig. 152). with hirsute blades, found 
Fig. 151. — Genchrus tribuloides. Plant, x | : two views of spikelet and fertile floret, 
X 10. 
from New Jersey to Florida, and A. ftoridanum Chapm.. a stolonif- 
erous perennial, with glabrous blades, confined to Florida. The 
latter often provides abundant pasture. 
