IOWA ACADEMY OF SCIENCES. 
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Carduus. 
700. C 
701. C 
702. C 
703. C 
704. C 
. lanceolatus L. {Cnicus lanceolatus Hoffm.) 
Abundant in open ground. 
. altissimus L., {C. altlssimiis Willd.) Fields and 
roadsides; common. 
. canescens canescens Nutt. (C. undidatiis var. 
canescens Gr. 
. discolor (Muhl.) Nutt. {C. altissimus discolor 
Gray.) With the preceding; common. 
. arvensis L. (C. arvensis Hoffm.) Becoming 
quite common. 
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