296 LESSONS IN AGRICULTURE 



duce seed and then die. To destroy this class of weeds, 

 pull them up by the roots the first year or prevent them 

 from seeding the second year. Burdock, bull thistle, 

 and mullein belong to this class. Perennials are those 

 plants that seed every year but whose roots live on from 

 year to year. The only way to eradicate the perennials 

 is to destroy them root and branch. These are the hard- 

 est of all to kill. The Canada thistle, ox-eye daisy, the 

 fleabanes, sorrel, and common sour dock belong to this 

 class. When such weeds are allowed to spread they soon 

 take possession of the farm. 



Practical Exercises 



1. Study of Field Collections of Weeds 

 Gather six or seven different kinds of weeds roots, 

 stem, leaf, and all and take them into the school room 

 for study. Answer the following questions regarding 

 each of the weeds you have collected : 

 Name of the Weed 



1. Kinds of soil in which it thrives best. 



2. Calculate number of seeds. 



3. How are the seeds scattered ? 



4. When ripe? 



5. At what time in the growing season do they ger- 

 minate ? 



6. Does the young plant grow rapidly or slowly? 



7. What kind of roots does the plant have ? 



8. When you cut it off does a new plant come from 

 the same place? 



9. Does plowing through a patch of weeds increase 

 their number ? 



