20 



WEED FLORA OP IOWA 



NATURAL CONDITION 



Date 



S. D. (7). 



Tenn. (2): 

 Nearly ripe 



Washington, D. C. (S): 



Cut July 1, very young 



Cut July 24, early 



bloom 



£ 



8.17 



3.20 

 74.2H 

 68.40 



31.25 

 31.77 

 5.59 

 8.14 



fc 



10.53 

 5.00 

 4.39 

 2.86 



S-t-i cu 

 fc 





e.9t 



WATKR FREE SUBSTANCE 



Green Foxtail (Setaria viridis (L.) Beauv.). 



Description. — An erect annual from 1-3 ft. high ; leaves 4-12 in. 

 long, with rough margins; greenish, more or less compound cyl- 

 indrical spikes from 1-5, or even in some cases 6 in. long; bristles 

 few, much longer than the spikelets ; spikelets % in. long, the chaff 

 of second and third glumes as long as the minute chaff of the 

 fourth glume, the latter being dotted and striate. A single head 

 produces an enormous number of seeds. 



Distribution. — This European grass is common in North Amer- 

 ica, especially eastward. It is found everywhere in the state, more 

 particularly in corn fields, gardens, and in vacant places. 



Extermination. — The same method of extermination should be 

 used for this weed as for pigeon grass. 



