The value of this book is not in new knowledge, but in the simple statement of the most important facts relating to some of our common trees, individually and collectively considered.  A knowledge of trees and forests adds vastly to the pleasures of outdoor life.  The more we study trees and the more intimate our knowledge of the forest as a unit of vegetation in which each tree, each flower, each animal and insect has its part to play in the complete structure, the greater will be our admiration of the wonderful beauty and variety exhibited in the trees and woods about us.

J.W.  TOUMEY,
Director, Yale University Forest School.

New Haven, Conn.,
June, 1914.

STUDIES OF TREES

CHAPTER I

HOW TO IDENTIFY TREES

There are many ways in which the problem of identifying trees may be approached.  The majority attempt to recognize trees by their leaf characters.  Leaf characters, however, do not differentiate the trees during the other half of the year when they are bare.  In this chapter the characterizations are based, as far as possible, on peculiarities that are evident all year round.  In almost every tree there is some one trait that marks its individuality and separates it, at a glance, from all other trees.  It may be the general form of the tree, its mode of branching, bark, bud or fruit.  It may be some variation in color, or, in case of the evergreen trees, it may be the number and position of the needles or leaves.  The species included in the following pages have thus been arranged in groups based on these permanent characters.  The individual species are further described by a distinguishing paragraph in which the main character of the tree is emphasized in heavy type.

The last paragraph under each species is also important because it classifies all related species and distinguishes those that are liable to be confused with the particular tree under consideration.

GROUP I. THE PINES

[Illustration:  Fig. 1.—­Twig of the Austrian Pine.]

How to tell them from other trees:  The pines belong to the coniferous
    class of trees; that is, trees which bear cones.  The pines may be
    told from the other coniferous trees by their leaves, which are in
    the form of needles two inches or more in length.  These needles
    keep green throughout the entire year.  This is characteristic of all
    coniferous trees, except the larch and cypress, which shed their
    leaves in winter.

[Illustration:  Fig. 2.—­Twig of the White Pine.]