CHAPTER IV. 



ROOTS, THEIR KINDS, MECHANICAL WORK AND 

 STRUCTURE. 



43. 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 reservoirs are seen in the sweet 

 potato, the tuber-rooted sunflower, 

 dahlia, carrot, parsnip, etc. In other 

 cases food materials are held in re- 

 serve during certain seasons in large 

 roots of trees, or in roots of peren- 

 nial or biennial plants, where they 

 are not specialized as food reser- 

 voirs. 



ROOT SYSTEM. 



44. The root system of a plant 

 includes all the roots of a single plant, 

 but has special reference to the form, 

 the branching of the system as a 

 whole determined by the mode, ex- 

 Tap roots o^par'snip and carrot, tent, direction and character of the 

 turs fleshy nes are als called Cr wn branching. There are several types 



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