138 ROOTS 
In anchoring the shoot most soil roots perform an important 
function, except in those plants with stems prostrate on the ground 
or climbing supports. In plants with upright stems, as in trees, 
the strains due to winds and gravity when the plant is bearing 
foliage and fruit is often enormous. However, the root system 
is usually able to hold the plant in place, although the strains 
may break off branches or even the main stem. It is by spread- 
ing laterally and profusely branching, that roots become so firmly 
attached to large masses of soil that they can endure enormous 
strains. 
In addition to anchoring the plant and furnishing it water and 
mineral matter, in many plants the roots function as storage or- 
gans, in which some of the food made by the shoot each year is 
stored for use in the development. 
of new shoots each succeeding year. 
This function is especially obvious 
in many plants which die down in 
the fall and grow up again in the 
spring. 
Thus the root depends upon the 
shoot for food while the shoot de- 
pends upon the root: (1) for water 
and mineral matter; (2) for an- 
chorage; and (3) often as a storage 
organ. 
Types of Root Systems. — There 
are various irregularities among 
root systems, due to the altera- 
Sei tions which a root system must 
ee, make in adjusting itself to obstruc- 
KA, v4 tions and the uneven distribution 
\ sy of water and mineral matter in the 
soil. For this reason root systems 
Fig. 122.— The fibrous roots are less symmetrical than shoots. 
of Corn. However, despite these irregulari- 
ties there are some inherent differ- 
ences that are so regular as to be typical of certain plants. 
In the Corn, Wheat, Oats, and Grasses in general, there is the 
type of root system, known as the fibrous root system, in which 
there are no dominant main roots, but all roots are small and with 
