CHAPTER VII. 



THE ROOT. 



'* The root, is that part of a plant by which it attach- 

 es itself to the soil in which it grows, or to the substance 

 on which it feeds, and is the principal organ of nutri- 

 tion." This definition does not apply to those plants 

 which float in the water without any attachment, but it 

 embraces every kind of root, which the student, whose 

 observations are not extended to aquatic vegetables, 

 will probably find. 



It applies to the branching root, by which trees., 

 shrubs, and many perennial plants are nourished and 

 supported. Like the stem, it is subdivided into numer- 

 ous, branches, some of which penetrate deep into the 

 earth, and others creep extensively beneath its surface, 

 But in whatever way it is subdivided, its branches al- 

 ways terminate in minute filaments or radicles, which 

 alone abstract nutriment from the earth. 



It applies to the fibrous root, Fig. 9, which consists 

 merely of slender fibres, that convey nourishment to 

 the basis of the stem, as in most grasses and annua! 

 plants. 



It applies to the creeping root, Fig. 15, which ex- 

 tends horizontally beneath the earth's surface, occa- 

 sionally sending up stems at a distance from the parent 

 plant, as in Mint. 



It applies also to other varieties. One of these is 

 the tuberous root, which consists of one or more fleshy 

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