The Stem. 



consists of one or more leaves, attached to the distal* end 

 of a portion of the stem. The part of the stem to which 

 the leaf or leaves are attached is called a node and the 

 part below the node, or in the stem as a whole, the part 

 between, the nodes, is called an internode. 



The nodes are -distinctly marked 

 in the younger stems of most plants 

 by a slight enlargement or by leaf- 

 scars, if the leaves have fallen (Fig. 

 35). The nodes are centers of vital 

 activity and are the points at which 

 lateral growing points (buds (128)) 

 are normally formed, and whence 

 roots usually start first in cuttings 

 and layers (358, 349). 



117. The Stem Lengthens by Elon- 

 gation of the Internodes, as well as 

 by the formation of new ones. As 

 the internodes soon attain their ulti- 

 mate length, it follows that the stem 

 lengthens only near its distal end. 

 An internode that has once ceased 



FIG. 35. Nodes (N); A, of 



the box eider, Negundo acer- elongating does not usually resume 



N 



; B, of the wild grape, j t hence the internodes of peren- 



Vitis riparia. 



nial plants that are only partially 



elongated at the close of the growing season in general 

 remain undeveloped. When growth is resumed in spring, 

 the formation of a comparatively long internode beyond 

 the very short ones of autumn usually forms a percepti- 

 ble ring about the shoot, which enables us to readily 



* Distal means farthest from the point of origin, i. e., the point at which 

 growth started. It is opposed to proximal, which means nearest the point 

 of origin. 



