DESCRIPTIVE MANUAL 



375 



Fig. 219-A. Distribution of Woolly Thistle. 



writer has seen it very abundant in both Wyoming and Colorado. 

 The species occurs in Emmet, Dickinson, Sioux, Plymouth, Wood- 

 bury, Cerro Gordo, Worth, Ida and Carroll counties in Iowa. 



Fig. 220. Woolly Thistle (Cirsxum canescens). In pastures and fields of 



northwestern and western Iowa. 



(Photographed by Pammel.) 



Extermination. — Correspondents sending this weed frequently 

 refer it to Canada thistle. It occurs not only in pastures and mead- 



