44. 



cutting the roots a sharp pungent odor is given off. 



MORNING GLORY FAMILY (ConVOlvuldCeae.) 



In addition to the weeds described below, we have the Euro 

 pean bindweed or morning glory, the southern morning glory 

 (Ipomoea purpurea) and related species. The sweet potato be- 

 longs to this family. 



Canada thistle (.Cirsium arvcnse). A common troublesome weed in gar- 

 dens, roadsides and sometimes in clover fields. Notice the perennial roots at 

 2, and the flowers at 3. (U. S. Dept Agr.) 



DODDER ( CllSCUttt Spp. ) 



The dodders are leafless excepting the small scales on the 

 stems, herbs of reddish or yellowish color, with thread-like stems 

 twining around the plants upon which they live. They pierce 

 the plant with small and short rootlets which are called suckers 

 or haustoria. The seeds are small, yet there is stored sufficient 

 nourishment in them to give the embryo a start. The seed ger- 



