66 FARM AND SCHOOL PROBLEMS. 



How Roots Feed. 



We have aquatic, aerial as well as soil plants. Thus we 

 have roots that derive their food from water; those that feed 

 on other plants ; and those that derive their food from the soil. 

 The different kinds of roots are known therefore as water roots, 

 parasitic roots, and subterranean roots. And we have also the 

 aerial and the adventitious roots. 



Water Roots. 



Floating and immersed plants such as bladder wort and 

 horn wort grow in water and have water roots. 



Soil Roots. 



Soil or subterranean roots as those of alfalfa and clover 

 derive nourishment from the soil. 



Aerial Roots. 



Aerial roots of epiphytes or air plants get their nourishment 

 from the air as "Spanish moss," and in some plants they are 

 subsidiary to soil roots and serve the purpose of climbing roots 

 for vines. 



Parasitic Roots. 



The mistletoe and dodder are examples of plants that derive 

 their nourishment by having roots that penetrate the substance of 

 other plants. 



Adventitious Roots. 



The gardener takes advantage of plants that grow adven- 

 titious roots from nodes and buds, and by layering or burying 

 part of a vine or the limb of a tree, he can propagate new plants. 



In summing up the work of roots we may state in a general 

 way that they serve five important purposes: 



1. To prepare food by means of acid and bacteria. 



2. To absorb food through root-hairs by osmosis. 



3. To serve as anchors and braces for support. 



4. To aid in the propagation of plants. 



5. To serve as food for plants and animals. 



