A Hairy Vetch 



Here a leguminous plant, cousin to the peas and beans, is 



shown with both top and root, to illustrate the luxuriant growth 



of the foliage, and the nodules on the roots that enable the plant, 



thanks to the nitrifying bacilli that inhabit them, to take up a 



supply of nitrogen from the air. These plants may have 



the most luxuriant foliage, even when growing on 



leached and barren soil, that will scarcely 



support other types of vegetation. 



