[Chap. XXXV VEGETATIVE MULTIPLICATION 



401 



Fig. 175. A miniature clone of redwood trees which originated vegetatively as 

 a group of sprouts from the roots of an older tree which has been cut down. 

 Photo from U. S. Forest Service. 



it was first selected from the progeny of a hybrid in 1853. Many other 

 varieties of cultivated plants are clonal varieties. Among them are the 

 several varieties of Irish potato, horse-radish, pineapple, rhubarb, coleus, 

 and raspberry, v^hich are perpetuated in cultivation by vegetative propa- 

 gation. The Carolina poplar trees too frequently seen along the streets 

 of cities are usually staminate trees which developed from cuttings 

 taken from other staminate trees. Most ornamental plants are perpetu- 

 ated by vegetative propagation. 



Vegetative multiplication may occur by either of two ways: by the 

 natural separation and further development of vegetative parts of a plant, 

 or by the further development of segments cut from a plant by man and 

 placed under various suitable conditions. Man promotes vegetative 



