64 HANDBOOK OF NATURE STUDY 



the burs, which are so annoying to man and beast. Can 

 you tell now how the seeds of the burdock are dissemi- 

 nated ? 



How destroyed. The burdock dies a natural death at the 

 end of the second season. Observe such dying plants. 

 During the first season, the root can be cut under ground 

 or the whole plant may be pulled up, when the ground is 

 very wet. Try that. Plants that have lived into the second 

 summer should be cut repeatedly, to prevent them from 

 blooming and producing seed. The burdock, like the 

 Canada thistle and the dog fennel, was introduced from 

 Europe. 



No. 7. The Sweet Clover. 



This plant is not troublesome in fields and gardens. In 

 Minnesota and Wisconsin it grows luxuriantly along roads, 

 on almost barren limestone, and in other waste places. In 

 its general appearance it resembles alfalfa, but is much 

 larger, being from two to seven feet high. It can scarcely 

 be classed as a noxious weed; its numerous white flowers 

 are quite fragrant and the plant has been cultivated for 

 fodder. If, however, it is allowed to grow along roadsides, 

 its profuse stalks and branches offer good shelter for hiber- 

 nating insects. Repeated mowing will keep it from seed- 

 ing, and ploughing or tilling of any kind will soon destroy it. 

 The flowers of the sweet clover resemble those of white and 

 red clover. If you can compare the different clover flowers 

 with flowers of beans and peas, you will notice a close re- 

 semblance. Beans, peas, vetches, and clovers belong to the 

 Pulse family. Do you know a tree whose flowers resemble 

 the flowers of the pea and the bean ? 



In some places a Yellow Sweet Clover is found, which in 

 general appearance is much like the white species, but is 

 smaller, from two to three feet high, and has yellow flowers. 



