MORE ABOUT WEEDS 149 



out the parts cut off. They can not bear good cultivation 

 and on rich soils they can probably be smothered out by 

 a close June sod. 



NOTE. 



A large number of very common weeds have been omitted. 

 Only those giving special difficulty to the farmer have been 

 described. Pupils should make a study of all the weeds to be 

 found in the neighborhood. Send to the Experiment Station in 

 your state for a bulletin on the subject of weeds and how to 

 destroy them, or send to Department of Agriculture, Washing- 

 ton, D. C, for Farmers' Bulletin No. 28. 



QUESTIONS AND EXERCISES. 



1. Why is it so hard to get rid of Canada thistles? 



2. How do burdocks spread? 



3. What weeds named in this chapter have underground 

 stems, or rootstocks? 



4. Why is the long-leaved plantain so objectionable in a 

 red-clover field that is to be cut for seed? 



5. Dig up and examine the roots of several common 

 weeds in your home locality. 



