ILLUSTRATED TERMS. 



The Root is the simplest organ of the tree. Its function is 

 to absorb nourishment and moisture from the soil, and in it to 

 firmly anchor the tree. 



Simple Primary Roots are those which grow singly from 

 the base of the seedling and form a main or tap root. They 

 then are either lost in their branches or they remain distinct 

 and send off side branches. 



Multiple Primary Roots are so called because several, or 

 a cluster of roots, grow simultaneously from the base of the 

 seedling. 



The Stems of trees are Arboreous — that is they differ from 

 those of other plants in forming a proper tree trunk. 



The Exogenous Stem (outside-growing) is the one that 

 belongs to all nortliern trees and shrubs. In it the pith, or 

 cellular tissue of the centre is, in large trunks, usually insignif- 

 icant in quantity, and is surrounded by a zone of wood which 

 in its turn is encased in an outer bark. That the wood occurs 

 in a larger proportion than do its other parts, is often the only 

 difference in arrangement between the stem of a young tree 

 and that of an herb. 



The Bark of a tree is divided into the inner and outer barks. 



The Inner Bark is called the Liber or Fibrous Bark. 



The Outer or Cellular Bark is divided into two layers: the 

 Green or Inner Layer and the Corky or Outer Layer. 



Sap-Wood or Alburnum is the outermost layers of wood 

 through which the sap most freely flows. 



Heart-Wood is the name given to the inner layers of wood. 



The Endogenous Stem (inside-growing) has no distinct 

 arrangement of pith, wood and bark. Throughout its whole 

 interior the threads of wood are irregularly scattered. 



Leaf-Buds are branches or leafy shoots not yet developed. 

 They may be either terminal or axillary. 



Terminal Buds grow at the summit of the stem or 

 branches. 



Axillary Buds grow in the axils of the leaves: they are 



■'"I 



1 



