of weeds. Grain fields are 

 sometimes mowed and sac- 

 rificed when very badly 

 contaminated with noxious 

 growth. 



In towns, mowing is the 

 most general method of de- 

 strowing the weeds of neg- 

 lected lots and roadsides. 



Sometimes annual weeds 

 are plowed under to kill 

 them. The thistle, bur- 

 dock, mullein, wild carrot, 

 etc., are biennials. They 

 produce a flat rosette of 

 leaves the first summer. 

 The next season the tall, 

 seed-bearing stalks are 

 formed. Such biennials 

 are checked by not letting 

 any of them come to seed 

 and by repeated and thor- 

 ough hoeing. 



Still another class of 

 weeds are the perennials, 

 wbich do not depend upon 

 seeds for dispersal, but pro- 

 pagate from the root or 

 root stalks and runners. In 

 this class are the field 

 daisy, Canada thistle, milk- 

 weed, quackgrass, etc. 

 Merely cutting oft' the tops 

 of these does no good, un- 

 less done many times till 

 the roots are starved to 

 death. They must be cut 

 off below the ground, up- 

 rooted, poisoned or smoth- 

 ered. 





(two 



LAMBS QUARTER 



RAGWEED 

 OF THE MOST COMMON OFFENDERS) 



