82 



in. long, tapering to a blunt point, the opposite end having a fringe of 

 minute hairs around the crown. The body of the seed is corrugated. 

 An average plant produces about 3,000 seeds. 



Time of riowering, July-October. 



Time of seeding, August-October. 



Dispersal — frequently as an impurity in clover and grass seed. 



Eradication. The method outlined for Canada Thistle may be 

 followed in eradicating this weed, but the plow may have to be used 

 more frequently than is advisable in combatting thistles. 



Fig 32. 



Wild Lettuce, Southern Thistle, or Trumpet-milkweed. 

 (Erroneously called Prickly Lettuce.) 



Lactuca Canadensis, (L). 



An annual or biennial plant with a leafy stem, which may attain 

 a height of seven feet. The leaves are deeply lobed, terminating in 

 an acute point, and have stalks or petioles, the lower ones being 

 smaller than those near the top of the stem. The stem branches at 

 its summit into a compound flower-cluster. The flowers are small, 

 yellow in color, and open only a few at a time. The seed is dark 

 "•own in color, flat and oval, with longitudinal ribs and a thread-like 

 ^ak at the apex, and possesses a small white tuft of hair (Fig. 32a). 



Time of flowering, June-October. 



Time of seeding, July -October. 



Dispersal — chiefly by the wind. 



Eradication. Where there is not much of it, pull and bum before 

 ripening. Where this cannot be done, use the same method as for 

 Mustard (Fig. 15). 



