676 



WEED FLORA OF IOWA 



/cT 



Fig. 524. Impurities found in Red Clover: 1, Bull Thistle; 2, Canada Thistle; 

 3, Green Foxtail iSetaria viridia) ; i, common Plantain (.Plantago nigelH) ; 

 5, Peppergrass (also found in Timothy) ; 6, Chicory; 7, Pigeon Grass 

 CSetaria glauca) ; 8, Crabgrass (Digitaria sanguinaUa) ; 9, Old Witch Grass; 

 10, Timothy; 11, Wild Carrot; 12, Pigweed (.Amaranthus retroflexus) ; 13, 

 Smartweed {Polygonum persicaria) ; 14, Lamb's quarters; 15, Dropseed 

 Grass (Muhleniergia) . 



(Drawings by Charlotte M. King.) 



Weed "host." 



Insect. 



Charlock (Sinapis 

 similar Crucifers 



arvensis) and 



Goosefoot (Chenopodium album) 

 Thistles (Girsium sp) 

 Sow Thistle iSonchus) 

 Dandelion (.Taraxdcuw,) and appar- 

 ently Docks (Rumex) 



Turnip Flea Beetle or "Fly" (Pftyl- 

 lotreta (.Haltica) nemorum) 



Cabbage and Turnip Gall Weevil 

 (Ceutorhynchus sulcicoUis) 



■ Mangold Fly (.Pegomyia betae) 



