WEEDS OF AGRICULTURE. 315 



them completely, they being so minute ; they will therefore 

 be more particularly mentioned hereafter. Of these eleven 

 weeds, whose seeds infest samples of corn, five are princi- 

 pally injurious to wheat; the others are partial, and more 

 common in barley and oats. 



12. HORSE GOLD {ranunculus arvensis). 



This species of frog-wort or corn butter-cup is an annual, 

 or rather, perhaps, a biennial, as it is sown and reaped 

 with wheat. The stem is erect, about a foot and a half 

 high ; upper leaves decomposite, segments narrow ; flowers 

 small, pale yellow ; seeds flat, convex on one side, concave 

 on the other; about one-sixth of an inch in diameter; 

 edges fringed with crooked prickles, with which the seeds 

 attach themselves to the fur or wool of animals. When this 

 plant is threshed with wheat, the seeds appear in the sample ; 

 and from which they are not easily separated by the com- 

 mon means. Wheat containing these seeds cannot be sold, 

 nor should they be used for seed, and the miller is sure to 

 object, as they belong to an acrid and dangerous family of 

 plants. When met with, they should be thrown out of 

 the sheaves by the reapers. 



