WEEDS 175 



Quack grass (Ayropyrum repens). This is a perennial species 

 whose slender and wide-creeping rootstock sends up new stems 

 at frequent intervals that later bear slender close-set spikes of 

 greenish flowers. It is one of the hardest of weeds to root out, 

 but this may be accomplished by planting fields infested with 

 it to some hoed crop and cultivating frequently. Though so 

 generally useless, this species is closely related to the wheat. 



Photograph from American Steel aud Wire Co. 



FIG. 124. The oxeye daisy on the border of a field 



Crab grass (Panicum sanguinale). This species, often called 

 finger grass, is a coarse annual that does not begin to grow 

 until the weather is quite warm and the cultivated crops well 

 started. At first the stems are erect, but later they lie upon 

 the soil with only the tips erect, and root wherever a joint 

 comes in contact with the earth. When pulling it up, every 

 root must be loosened or it will continue to thrive. The flow- 

 ering stems are topped by several slender spikes that radiate 

 from a common center. 



