COMPOSITE 



631 



wild in Europe, Canary Isles, Madeira, Algeria, Abyssinia, 

 and Eastern Asia, and has also become naturalized in the 



Fig. 257. — Cos lettuce, var. romana. (After Corbett.) 



United States, where it is often a troublesome weed. In 

 this country, L. scariola is distributed from New York to 



Fig. 258. — Head lettuce, var. capitata. (After Corbett.) 



Minnesota and Missouri. The close relationship between 

 L. sativa and L. scariola is shown by the fact that they readily 

 cross. 



