CHAPTER VI 

 REPRODUCTION 



Reproduction Without Seed. — We have already referred to 

 some of the methods of reproduction in plants. We have learned 

 that a bud is an undeveloped stem with its undeveloped leaves ; 

 and that the cuttings of many plants when placed in moist soil 

 or in water will grow readily ; that is, the buds expand, a root 

 system is developed and a new plant possessing a complete set 

 of organs like the parent is formed. In nature many plants, such 

 as the willow, shed twigs which catch in the soil and grow. This 

 growing of twigs explains the rapidity with which willows come 

 into existence along water courses. Many grasses and other 

 troublesome plants increase in number as a result of having the 

 underground stems torn in pieces by farming tools, thus per- 

 mitting each bud to form a new plant. We know that this power 

 of buds to grow makes it possible to perpetuate many valuable 

 varieties by cuttings, budding, and grafting. These methods 

 are the common practices of florists, nurserymen, orchardists 

 and others who wish to produce large numbers of plants of def- 

 inite varieties. 



Many plants are grown almost exclusively from the tubers 

 or bulbs which we now recognize as forms of stems (Chapter 

 IV), and many of these plants have partly or entirely lost 

 their power to produce seeds. Plants which have lost this 

 power to produce seeds must be grown entirely from bulbs, or 

 cuttings, or by budding or grafting. 



We know that, although roots do not generally produce 

 buds, many plants are propagated by shoots developed from 

 adventitious buds formed on the roots. The sweet potato 

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