CHAPTER TWENTY-FOUR 



VEGETATIVE MULTIPLICATION AND PLANT 

 PROPAGATION 



The development of new plants from roots, stems, and leaves 

 is called vegetative multiplication in distinction from reproduc- 

 tion by seeds. Growers of plants make use of these natural 

 methods of multiplying plants, and in addition have devised 

 methods of artificially multiplying them by grafting, budding, 

 and the growing of cuttings. In the plant-growing arts these 

 methods are grouped under plant propagation. 



Vegetative multiplication. In the discussion of stems attention 

 was called to the fact that one of the advantages in underground 

 stems lies in the facility with which the plant may be multiplied. 

 From rootstocks arise new terminal and lateral buds that later 

 form new aerial shoots, and through the death of the older parts 

 of the underground stems these branches become separate plants. 

 Bulbs, corms, and tubers bring about vegetative propagation in 

 a similar way. 



Plants may multiply from the aerial vegetative parts also. 

 The stems of the black raspberry commonly bend over, and where 

 they touch the ground they form buds from which adventitious 

 roots and new upright stems develop. A grapevine will take 

 root where a node comes in contact with the soil. In the walk- 

 ing fern the tips of the leaves (Fig. 291) develop buds, roots, 

 and new plants when in contact with the soil. The strawberry 

 is an example of certain plants, in- 

 cluding many grasses, which have 

 horizontal branches (runners) on the 

 soil surface that take root at inter- 

 vals and produce new plants. In 

 Bryophyllum, a persistent weed m 

 cultivated fields of the West Indies, 

 the leaves when they fall to the '^'-' 

 ground develop new plants from the ^^"- "?• bryophyllum leaf, with 



° ^ ^ \ young plants starting from the notches 



notches in their margins. in the margin. 



225 



