GRASSES OF IOWA. 



463 



A few members of the mustard family are troublesome in 

 meadows and pastures of this state. One of these, pepper 

 grass (Lepklium apetalum), is abundant throughout the state, 

 especially in timothy meadows. The flowers are small and 

 greenish- white; the seeds are light brown, elongated, with a 

 prominent ridge on one side. This weed is frequently found 

 in timothy seed. The brown color of the seed attracts the 



Fig. 230. B.OTse nettle, (Solanum carolineme) . Troublesome weed. When once 

 established, difficult to exterminate. (Dewey, Div. Bot. U. S. Dept. Agrl.) 



attention of the seedsmen. Prof. P. H. Rolfs* identified this 

 as one of the chief admixtures in timothy seed. 



Canada thistle {Gnicus arvensis), though common in eastern 

 meadows, is as yet not common in the state, although it some- 

 times occurs in meadows. It differs from other thistles in its 

 small "flowers," leaves, and the perennial character of the 

 plant. 



•Bull. la. Agrl. Exp. Sta. 13. 



