IMPORTANT POISONOUS PLANTS 



137 



Compositae. Composite Family. 



Lactuca Scariola L. Prickly Lettuce. 



Common across the continent, also the var. Integra. Said to be poisonous. 



Cichorium Intybus L. Chicory. 



It has become widely naturalized in the north and west. When fed in large 

 quantities to dairy cattle it imparts a bitter flavor to the milk and butter. It 

 contains the bitter glucoside chicorin. 



Iva xanthiifolia Nutt. Marsh Elder. Half-breed Weed. 



Western Wisconsin, Red River Valley, south and west to the Rocky Moun- 

 tains. Said to cause hay fever. 



Ambrosia artemisiaefolia L. Common Ragweed. 



The pollen of this plant is suspected of causing hay-fever. 



122 



Fig. 19k. Spiny Clotbur (Xanthium spinosum). Injurious in a mechanical way. Fig. 191. 

 Prickly I<ettuce (Lactuca Scariola). Said to be poisonous. (Bentham). 



Ambrosia trifida L. Great Ragweed. 



The pollen of this species is said to produce an irritating action upon the 

 mucous membrane. 



Xanthium spinosum L. Clotbur. 



Maine to Texas. It causes mechanical injuries. 



Xanthium canadense Mill. Cocklebur. 



Young seedlings of this plant are poisonous to horses. Several cases of 

 poisoning to hogs have been reported in this state. 



Xanthium strumarium L. Cocklebur. 



Poisonous like the preceding. This species is not common in the state. 

 Contains the glucoside xanthostrumarin. 



