CHAPTER V. 



ROOTS, THEIR KINDS, MECHANICAL WORK AND 

 STRUCTURE. 



50. There are two kinds of work which nearly all roots per- 

 form: First, the absorption of water and food solutions; second, 

 that of attachment and support 



for the plant. In addition there 

 are cases where roots of certain 

 plants serve other purposes as 

 well, for example, where they serve 

 as storehouses for food. In some 

 of these the root takes on a special 

 form which enables it to hold large 

 reserves of food. Such food reser- 

 voirs are seen in the sweet potato, 

 the tuber-rooted sunflower, dahlia, 

 carrot, parsnip, etc. In other 

 cases food materials are held in 

 reserve during certain seasons in 

 large roots of trees, or in roots of 

 perennial or biennial plants, 

 where they are not specialized as 

 food reservoirs. 



ROOT SYSTEM. 



51. The root system of a 

 plant includes all the roots of a 

 single plant, but has special refer- 

 ence to the form, the branching of 



the system as a whole determined Tap roots O f g pa 3 r 4 s ' nip and carrot . 

 by the mode, extent, direction and ^ e h rs fleshy ones "* also called cr ? wn 



