40 



C()RN 



food. From 22 to 28 brace roots usually appear at each node. If the 

 weather is stormy and the corn has a tendency to blow over, these 

 brace roots grow very rapidly. 



BR.\rE ROOTS 

 St.alk showing brace roots at nodes above the ground. 

 Note also the rudimentary roots just api^earing at 

 tlie two upper nodes. 



STRUCTURE. The outermost layer of a young root is a single 

 cylinder of cells termed the "piliferous layer." This layer, when near 

 the newly formed tip of the root, is the absorbing surface for soil 

 moisture and plant food. The root hairs are merely projecting por- 

 tions of the individual cells of this layer. The fact that thi.s layer is 

 absorptive differentiates it from the epidermis of the stem. 



Immediately beneath the piliferous layer is the "cortex" which is 

 thick and consists chiefly of parenchymatous or thin-walled cells. The 



