36 



THE ROOT. 



Fig. 28. 



and stem should be founded, is contained in the first part of our 

 definition, that the root is the descending part of the axis of a 

 plant. If it descends it is a root, and if it ascends it is a stem ; 

 we mean, of course, when they meet with no physical impedi- 

 ment. 



67. The forms of roots are various, 

 and receive different names in the de- 

 scriptions of plants. Although various 

 divisions have been made by different 

 Botanists, yet great discrepancies exist, 

 among them. We shall describe only 

 the most common forms. 



(1.) Branching Hoot, or Radix ra- 

 mosa, Fig. 28. These roots are such 

 as subdivide in the earth in a man- 

 ner similar to the divisions of the 

 stem, and are found exhibited in the 

 forest trees and shrubs. This variety 

 forms the true type of roots ; and is 

 the one from which our ideas of this 

 organ are formed, as distinguishing it 

 from the other organs of the plant. 



Fig. 29. (2.) The Fibrous Boot, or Radix fibrosa. 



This variety consists of numerous fibers pro- 

 ceeding from the neck of the plant, and may 

 be seen in most grasses and grains. Fig. 29. 



(3.) Fasciculated 

 roots. When the 

 fibers of roots be- 

 come enlarged by 

 the deposition of 

 starch, they form 

 this variety of root, 

 as exhibited by the 

 Dahlia, Peony, (fee, Fig. 30. 



(4.) The Tap root, or conical root, 

 when the root sinks perpendicularly 

 into the earth, and topers regularly 



from the base to the apex with very few fibrous radicles, as in 

 the Beet, Parsnip, &c, Fig. 31. Tins variety contains some of 

 the most important garden vegetables, and it is seldom found 



Pig. 30. 



Fasciculated roots. 



67. What is a branching root ? What is a fibrous root? What is a fas- 

 oioulated root ? What is a tap root? 



