MORE ABOUT WEEDS 



147 



Prickly Lettuce (called, also: Wild lettuce, Milk this- 

 tle, English thistle, Compass plant), Lactuca Scariola. 

 This plant is occupying 

 waste grounds in many 

 parts of the country. It 

 is an annual, and in- 

 creases only by seed, but 

 it seeds very freely and 

 the young plants are 

 so strong that it spreads 

 very rapidly where per- 

 mitted to do so. It has 

 often been mistaken for 

 the sow thistle and some- 

 times for the Russian 

 thistle. 



The prickly lettuce is 

 closely related to the 

 common garden lettuce, 

 which it resembles in the 

 seed-bearing stage. The 

 stem is smooth, with the 

 exception of a few scat- 

 tered prickles. The 

 plant begins to bloom in July, and produces a few blos- 

 soms each morning after that time until killed by frost. 

 An average plant has been estimated to bear more than 

 8,000 seeds. 



Repeatedly mowing the plants as they come into bloom, 

 or earlier, will subdue them. Thorough cultivation with 

 a hoed crop, by means of which the seed in the soil may 



FIG. 83. Prickly lettuce; a, plant 

 bloom; b, leaf; c, seed, magnified. 



