76 PLANT PROPAGATION 



extremely simple. Plants bearing rhizomes are propagated 

 either by separating naturally at the close of the growing 

 season, or by being divided into as many parts as there 

 are buds. Each part of the rhizome bearing a bud will 

 develop into a new plant. The divided parts are treated 

 in much the same way as bulbs. However, a little experi- 

 ence is necessary in their management if the best results are 

 to be expected. 



Tubers. — A tuber is the localized thickening of a shoot. 

 It is usually subterranean and is rarely ever found above 

 ground. Tubers bear scale leaves which are analogous to 

 the leaves on ordinary stems. The scale leaves are small 

 and insignificant and sometimes are not recognized in 

 mature specimens. The scale leaves are always at some 

 distance from each other, and they .never overlap. The 

 buds, which develop in the axils of the miniature scale 

 leaves, are called eyes. These are indicated on the tuber 

 by ridges or lines of protuberances. Generally, tubers are 

 extremely perishable organs, and they can only carry the 

 life of the plant from one season to the next. Plants bear- 

 ing tubers are easily transported long distances because of 

 the reduced and compact form. 



Tubers reproduce themselves by offshoots. A fully 

 formed tuber becomes detached from the upper part of the 

 plant by the decay of the slender stem. This connection 

 of the tuber with the parent has previously supplied it with 

 food. After varying periods of rest a stem springs from the 

 eyes of the new tubers, and these in turn bear tubers similar 

 in structure to those of the parent. 



Propagation by tubers is extremely simple. It consists 

 either in planting the whole tuber or a portion of it, each 

 part of which must contain an eye or a bud. 



Procumbent Stems. — A procumbent stem is a stem that 

 either droops to the ground or trails over it. Usually the 

 habitat of this class of plants will be found to be such that 

 erect plants are unable to maintain themselves, and the 

 drooping habit is acquired in order that the plant is able 

 to live. A poor, sandy soil, a windy hillside, a rocky or 

 rough piece of ground is the habitat wliich is usually 



