INTRODUCTION xv 



tion, even if you are sure about only the sugar maple and 

 the white birch. 



The characters to note in studying trees are: leaves, 

 flowers, fruits, bark, buds, bud arrangement, leaf scars, and 

 tree form. The season of the year determines which 

 features are most prominent. Buds and leaf scars are the 

 most unvarying of tree characters. In winter these traits 

 and the tree frame are most plainly revealed. Winter 

 often exhibits tree fruits on or under the tree, and dead- 

 leaf studies are very satisfactory. Leaf arrangement may 

 be made out at any season, for leaf scars tell this story after 

 the leaves fall. 



Only three families of our large trees have opposite 

 leaves. This fact helps the beginner. Look first at the 

 twigs. If the leaves, or (in winter) the buds and leaf 

 scars, stand opposite, the tree (if it is of large size) belongs 

 to the maple, ash, or horse-chestnut family. Our native 

 horse-chestnuts are buckeyes. If the leaves are simple the 

 tree is a maple; if pinnately compound, of several leaflets, 

 it is an ash; if palmately compound, of five to seven leaflets, 

 it is a horse-chestnut. In winter dead leaves under the 

 trees furnish this evidence. The winter buds of the horse- 

 chestnut are large and waxy, and the leaf scars look like 

 prints of a horse's hoof. Maple buds are small, and the 

 leaf scar is a small, narrow crescent. Ash buds are dull 

 and blunt, with rough, leathery scales. Maple twigs are 

 slender. Ash and buckeye twigs are stout and clumsy. 



Bark is a distinguishing character of many trees — of 

 others it is confusing. The sycamore, shedding bark in 

 sheets from its limbs, exposes pale, smooth under bark. 

 The tree is recognizable by its mottled appearance winter 

 or summer. The corky ridges on limbs of sweet gmn and 



