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Carduus discolor, (Muhl.) Nutt. Field Thistle. 

 Cnicus discolor, Muhl. 



On prairies in the Minnesota and Sioux valleys. 



Carduus Virginianus, L. Virginian Thistle. 

 Cnicus Virginianus, Pursh. 



In woods and thickets in the Minnesota and Sioux 

 valleys. 



Carduus undulatus, Nutt. Wavy-leaved Thistle. 

 Cnicus undnlatus, Gray. 



On plains and prairies throughout the state. 



Carduus ochrocentrus, (Gray.) Green. Yellow-spined 

 Thistle. 

 Cnicus ochrocentrus, Gray. 



In dry soils in the Black Hills. 



Carduus Plattensis, Rydberg. Prairie Thistle. 



In sandy soils in the southwestern part of the state. 



Carduus Drummoiidi, (Gray). 

 Cnicus Drummondi, Gray. 



In damp meadows in the Black Hills. 



Carduus Caruovireiis, Rydberg. 



Collected near Sylvan lake in the Black Hills, by 

 Mr. L. W. Carter. Specimens sent Dr. Rydberg were 

 identified as this species. 



Carduus arvensis, (L.) Robs. Canada Thistle. 

 Cnicus arvensis, Hoff. 



Sparingly naturalized in the Sioux valley. 



Centanrea Cyanus, L. Blue Bottle. Corn Flower. 

 Roadsides near Hot Springs in the Black Hills. 



