PROPAGATION BY IXARCHING. 63 



of six years it will be only a leaf enlarged and much thick- 

 ened. It makes no further growth, as there is no bud from 

 which a plant can extend upward. But if the leaf is cut 

 so as to include the bud in the axil we soon have roots and 

 plant growth. 



Again, if we make a dahlia cutting without a bud at the 

 base we can develop a flowering plant with supporting roots, 

 but we find no tubers below. In this case we have buds 

 for upward growth, but no bud below for tuber formation- 

 Still again, if we root the stem of a gloxinia leaf it will 

 continue to grow as a leaf like the Hoya carnosa, but it 

 will develop at the lower end of the petiole a small tuber, 

 which can be dried off, planted, and it will produce a per- 

 fect plant. 



On the same principle, if the crown buds of the tubers 

 of dahlia, peony, or rhubarb are broken or cut off we 

 will have root enlargement and growth below the ground, 

 but they will perish after a longer or shorter period, as 

 they cannot develop buds for upward growth. On the 

 other hand, we have tubers like the potato that have eyes 

 or buds for growth at many points, and we have leaves, 

 like the rex begonia, that when pegged down on moist 

 sand of the cutting-bench will develop buds and make root 

 and top growth at every point where wounded, as shown 

 in Fig. 31. 



68. Division of Perennials, Tubers, and Rootstalks. 

 About all the perennial flowers and garden plants, such as 

 perennial phlox, hemerocallis, funkia, fraxinella, and 

 pie-plant, may be divided by separations, including a bud 

 at the top of each section. In some cases even biennials 

 may be perpetuated by division. As an instance, the 

 double hollyhock flowers the second year from the seed 

 and the year following, when the plants die. But if the 

 fleshy roots are divided after the second year's flowering 



