CHAPTER II 



ROOTS 



The grand divisions of higher plants are root, stem, leaf, 

 flower, fruit. There are other conspicuous external organs, 

 as bark, branch, bud, spines, thorns, prickles and tendrils, but 

 these are lesser divisions that can be best treated as parts of 

 the greater ones. The major divisions begin at one pole of the 

 plant axis and proceed to the opposite pole, and in this orderly 

 manner, from root to fruit, a chapter for each, they are best 

 treated. 



9. The root distingnished from the stem. — In all seedling 

 plants there is a descending and an ascending part. The part 

 which grows downward is the I'oot; that which grows upward, 

 the stem. The point of juncture is the croivn or collar, terms 

 used almost solely by fruit-growers. Roots do not give off 

 branches in regular order as do stems ; they do not bear buds 

 in regular intervals, hence have not nodes and intemodes as 

 have stems ; the growing point of the root is protected by a root- 

 cap, while the growing point of the stem is not so protected; 

 roots of plants with which pomology deals may be white, yel- 

 low, red, brown, or black but are never green, that is do not 

 possess chlorophyll. The functions of root and stem furnish 

 even more marked differences, but a discussion of functions in 

 this text would lead too far afield. 



Perhaps it should be said that all roots do not descend into 

 the ground, and that all underground parts of plants are not 

 roots. The exceptions, however, are not of gi'eat concern in 

 systematic pomology. 



10. The root system. — The first root that breaks from a seed 

 is the primary root. This takes a downward course which it con- 

 tinues by growth near its tip. If this primary root continues 

 to grow throughout the life of a plant, it becomes the tap-root of 



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