39 



Fig. 25. Chaetochloa glauca (Linn.) Scribn. (Setaria glauca Beauv.) YEL- 

 LOW FOXTAIL.— a, A spikelet showing the second glume, the upper portion 

 of the fourth or flowering glume and the numerous bristles which surround the 

 spikelet at the base; b, a spikelet showing the back of the first and third glumes. 

 Figures 65 to 68 in Bui. 7 and 402 and 403 in Bui. 17 illustrate other species of 

 this genus. 



25. CHAETOCHLOA Scribn. U. S. Dept. Agr., Div. Agros. Bui. 4: 38. 1897. 

 (Setaria Beauv., 1812, not Acharius, 1798.) Spikelets hermaphrodite, 1-flowered 

 or sometimes with a staminate flower below the hermaphrodite terminal one, 

 surrounded by few or many persistent, awn-like branches which spring 

 from the pedicels below the articulation of the spikelets, and impart to the 

 dense cylindrical or somewhat interrupted spikelike panicles a bristly appear- 

 ance. Glumes as in Panicum, awnless. Stamens 3. Styles distinct; stigmas 

 plumose. Grain included within the hardened flowering glume and palea, 

 but free from them. Annual or perennial grasses with flat leaves and bristly, 

 spikelike panicles. 



Species about 40 in the warmer regions of the world. Twenty-eight species 

 occur in North America, chiefly in the southern and southwestern United 

 States and Mexico; three are cosmopolitan weeds. 



