MISC. PUBLICATION 16 2, U. S. DEPT. OF AGRICULTURE 



Tree increases each yea' 

 height and spread of Branches 

 by adding on rrgw growth of 

 twigs. 



CROWN 



Air SuppKes carbon, 

 the principal food of 

 the treeXaken "in 

 through the leaves. 



hairs fa So 



ling 



n ere lo ir» 



Figure 1. — How a tree grows. 



The buds, root tips, and cambium layer are the growing parts of the tree. Water 

 containing a small quantity of minerals in solution is absorbed by the roots, 

 carried up through the sapwood to the leaves and there combined with carbon 

 from the air to make food. This food is carried by the inner bark to all 

 growing parts of the tree, even down to the root tips. 



