130 MORE ABOUT WEEDS 



alone, spread over a square rod or more of ground. It 

 may spread, also, by its seeds, but this is not so likely, as 

 most of the seeds will not germinate. 



The following are the best methods for the destruction 

 of the Canada thistle : 



(1) After manuring the soil, plant it thickly with 

 clover. When the thistles are in bloom, mow the clover, 

 cutting down every thistle. When the clover is again 

 up high enough to cut, plow it under carefully, harrow 

 and roll. Keep the field well cultivated till late in the 

 fall. Plant grain or grass the next spring. 



(2) Pour oil of vitriol on the stump left in the 

 ground after cutting off the thistle as close as possible. 



(3) Apply salt liberally to each stump. Turn in 

 sheep or goats. - They will usually eat the thistles close 

 to the ground, and prevent their growth. 



(4) Seed liberally with any grass that will grow well 

 on the ground. The thistles may be choked out by this 

 method. 



The Burdock (called, also: Great lappa, Gobo, Lappa 

 officinalis, L. major, L. edulis, etc.), Arctium Lappa. 

 This coarse, mammoth, offensive weed, with its large 

 brown burs that stick to the clothing and to the coats of 

 animals, is familiar to all. 



In Figure 68 is shown an illustration of a portion of 

 the stems of two varieties of this plant in flower. At i, 

 is a branch of the small variety (Minor), and, at 3, one 

 of the more common varieties (Major). At 2, a single 

 flower is shown magnified. A shows magnified views of 

 the seed, and B shows the seed natural size. 



Though not very troublesome in cultivated ground, 



