"WEED MIGRATION 



749 



1902 (Myrhe); Audubon, 10O5 (M. C. Griffith); Graettiuger, 

 1906 (E. L. George) ; Clarion, 1909 (Melhus) ; also in Lorimer 

 (Loehrie) ; Blairsburg (J. M. Hall) ; Oelwein (J. Thompson) ; 

 Muscatine (F. Reppert) ; Reading (Dr. McGlanahan) ; Griswold 

 (R. E. Pierce) ; Randall (C. & G. R. Christianson) ; Hartley (H. R. 

 Poblenkamp) ; Garrison (J. Grayson) ; Roland (E. N. Waugh) ; 

 Kossuth (S. A. Merrill) ; Cedar Palls (C. E. Daily) ; and Wool- 

 stock (A. P. Reynold). 



Woolly Thistle {Cirsium canescens). 



This plant has been reported from several states north and west 

 of the Mississippi. In Iowa it occurs chiefly in the northern half 

 of the state, having been reported by A. S. Hitchcock in 1889, as 

 growing near Sioux City. Later it was reported from Sioux City 

 by Pammel, 1895; Armstrong (Cratty), 1897; Webster City 

 (McCoy), 1901; Onawa (Fletcher), 1902; Le Mars, 1902 (Wm. 

 Long) ; Charter Oak, 1903 (C. N. Weed) ; Pisgah (L. H. Raymond), 

 1903; Rolfe (J. B. JoUiffe), 1908; Lu Verne (W. F. Blumer), 



FiQ. 562. Woolly Thistle (.Cirsium canescens). Originally along the Missouri 

 and adjacent territory. Now spreading eastward. 1, head ; 5, single flower ; 

 6, achenium ; 7, stamens and style ; a, stigma enlarged ; 8, pollen grain. 

 (Drawings by Charlotte M. King.) 



