Description of Tumbling Mustard. 171 



that plants from seeds which have fallen 

 early in the season will in turn mature 

 before the coming of winter. 



Frenchweed will grow least vigorously 

 on stiff clays, and most luxuriantly on the 

 vegetable soils of the prairies. It harms 

 grain crops much more than pasture or 

 meadow or cultivated crops, and it does 

 m.ore injury to grain crops which ripen 

 early than to those which ripen late. 



Frenchweed is distributed through the 

 medium of the seeds. They are carried 

 along with the seeds of cereals amid which 

 they have grown. They may also be dis- 

 tributed in manure and in the droppings of 

 cattle, and to some extent they are con- 

 veyed by water and carried by wind. The 

 seeds are possessed of great vitality, but 

 they will not germinate unless they are near 

 the surface of the soil. 



(4) TUxMBLING MUSTARD. 



Tumbling mustard (Sisynibrimn altissi- 

 mum) is another bad weed of the mustard 

 family. In some localities it is known 

 simply as "Tumble weed," but in central 

 Europe it is called Hungarian mustard. It 

 is thought that it was brought to this con- 



