III. 



WILD LETTUCE AS WEED AND COMPASS PLANT 



The prickly lettuce is a plant closely resem- 

 bling the common garden lettuce, especially 

 the narrow leaved Cos varieties. The simi- 

 larity is more striking if we compare them 

 after the flower stalks have begun to appear. 

 There are in fact good grounds for believing 

 that the garden forms were derived from the 

 wild lettuce : a view held at one time by Bis- 

 choff, DeCandolle,and other authorities, who 

 wrote the Latin name of the garden forms 

 Lactuca Scariola var. sativa, instead of L. 

 sativa, as adopted by Linnaeus and adhered 

 to by most of recent writers. 



The plant is an annual, coming from seed 

 each year. Occasionally the seed germinates 

 in the fall, the plant making some grow-th be- 



*A portion of Bulletin No. 52 of the Indiana Experiment Sta- 

 tion, issued November 10, 1894. 



Likeness to 



cultivated 



lettuce 



