226 



General Botany 



These illustrations, which might be indefinitely multiplied, 

 show the importance of vegetative propagation in the increase 

 and spread of plants. In nature it is probable that vegetative 

 multiplication is as effective in spreading plants as is reproduction 

 by seeds. By the former method the young plant is able to start 

 more vigorously than a seedhng, because it is able to draw water 

 and food materials from the parent plant until its own root and 

 leaf systems are well developed. 



On this account, among wild herbaceous plants vegetative 

 multiplication frequently determines which species shall dominate 



/a habitat. Vegetative multipHcation, 

 for example, gives blue-grass the ad- 

 vantage over other plants in our 

 lawns. Cat-tails and water liHes fre- 

 quently exclude all other plants from 

 their habitats by this means. Grass- 

 lands the world over are dominated 

 by perennial grasses with underground 

 stems. Denuded soil areas near cities 

 are at first populated by annual weeds, 

 but in a few years are occupied by per- 

 ennials, which have gradually crowded 

 out the annuals. 



Vegetative propagation of cultivated 

 plants. In agriculture and horticul- 

 ture, vegetative propagation is rehed 

 upon for starting many cultivated 

 plants. Especially with plants that 

 do not usually produce seed, and de- 

 sirable hybrids and horticultural va- 

 rieties that do not come true from 

 seeds, is this method of propagation 

 used. Potatoes, mint, horse-radish, 

 sugar cane, sweet potatoes, and car- 



Ofice of Farm Management {J. S. Gates) 



Fig. 130. Underground bulb of 

 wild garlic, showing vegetative 

 multiplication by the formation of 

 three bulbs from the one planted. 

 The terminal bud of the original 

 bulb developed a flowering shoot, 

 and three of its lateral buds 

 formed the new bulbs. 



