DESCRIPTIVE MANUAL 



123 



Fig. 70. Nodding Chickweed (Cerastium nutans). Common in fields, waste 



places and streets, southern Iowa. 



(Photographed by Colburn.) 



Extermination. — This annual is easily exterminated by cultiva- 

 tion. "When it occurs in places that cannot be cultivated, like pas- 

 tures and lawns, iron sulphate at the rate of 100 pounds to a barrel 

 of water may be used. 



