32 



THE STEM, OR ASCENDING AXIS. 



The opposite, -where two branches stand on opposite sides of the same 

 node, as in the maple. 



Verticillate, where three or more branches, equidistant, encircle the 

 stem at each node, as in the pine. 



154. The angle of divergence in branches is also subject to definite rules 

 more obvious in the earlier stages of growth. "While the divergence is uniform in 

 the same species, it varies to every degree of the circle in different species, greatly 

 affecting the form of the tree. In general, without marking the exact degree, 

 branches are said to be erect (Lombardy poplar), spreading or obliquely ascending 

 (common), divaricate or at nearly a right angle (oak), deflexed (beach), and pendv.- 

 lous (weeping willow). 



155. Certain kinds of branches are noted for their tendency to 

 produce adventitious roots, and thus to become independent plants. 

 Nurserymen avail themselves of this property in propagation, and name 

 such branches cions, stolons, of sets, slips, layers, cuttings, and runners.-^ ^ 



156. The Sucker is a branch issuing from some underground por- 

 tion of the plant, leaf-bearing above and sending out roots from its own 

 base, becoming finally a separate, independent plant. The rose and 

 raspberry are thus multiplied. 



m 



a b c d f « . 



40. a, Slip (gooseberry) taking root, b, Cutting (grape) taking root, c, Stolons or layers arti- 

 ficially arranged for propagation, d, A mode of dwarfing (§ 140). e, Cions— process of graft- 

 ing. /, A Sucker. 



157. The Stolon or Layer is a branch issuing from some above- 

 ground portion of the stem, and afterward declining to the ground 

 takes root at or near its extremity, sends up new shoots, and becomes a 

 new plant. The hobble-bush and black raspberry do this naturally, 

 and gardeners imitate the process in many plants. 



158. The Cion is any healthy twig or branchlet bearing one or 

 more buds, used by the gardeners in the common process of grafting. 

 Slips and cuttings are fragments of ordinary branches or stems con- 



