WEEDS 



341 



10. In the following table the names in each line at the left of the 

 vertical line are those of cultivated plants ; the names at the right, 

 those of wild plants of the same family or even more closely related. 

 Explain in each case, as well as you can, why the cultivated plant would 

 be unable to maintain itself in competition with its wild relatives if 

 they were growing side by side. 



wheat, corn grasses occurring as weeds 



beets, spinach 



peonies 



garden strawberries 



scarlet sal via 



potato, tomato 

 lettuce 



pigweeds 



buttercups 



cinquefoils 



blue dooryard violets 1 



catnip 



Jimson weed, horse nettle, ground cherry 



dandelion 



11. How should we treat a lawn infested with dandelions? with chick- 

 weed? with undesirable grasses? 



Viola papilwnacea, V. sororia. 



