Studies of Trees.
by Jacob Joshua Levison.
PREFACE
In presenting this volume, the author is aware that there are several excellent books, dealing with one phase or another of tree life, already before the public. It is believed, however, that there is still need for an all-round book, adapted to the beginner, which gives in a brief and not too technical way the most important facts concerning the identification, structure and uses of our more common trees, and which considers their habits, enemies and care both when growing alone and when growing in groups or forests.
In the chapters on the identification of trees, the aim has been to bring before the student only such characters and facts as shall help him to distinguish the tree readily during all seasons of the year.
Special stress is laid in each case on the most striking peculiarities.
Possible confusion with other trees of similar appearance is prevented as far as possible through comparisons with trees of like form or habit.
Only such information is given concerning the structure and requirements of trees as will enable the reader better to understand the subsequent chapters. In the second half of the book, practical application is made of the student"s general knowledge thus acquired, and he is acquainted with the fundamental principles of planting, care, forestry, wood identification and nature study.
The author recognizes the vastness of the field he is attempting to cover and the impossibility of even touching, in a small hand-book of this character, on every phase of tree study. He presumes no further; yet he hopes that by adhering to what is salient and by eliminating the less important, though possibly interesting, facts, he is able to offer a general and elementary _resume_ of the whole subject of value to students, private owners, farmers and teachers.
In the preparation of Chapter VIII on "Our Common Woods: Their Identification, Properties and Uses," considerable aid has been received from Prof. Samuel J. Record, author of "Economic Woods of the United States." Acknowledgment is also due to the U.S. Forest Service for the photographs used in Figs. 18, 122 to 138 inclusive and 142; to Dr.
George B. Sudworth, Dendrologist of the U.S. Forest Service, for checking up the nomenclature in the lists of trees under Chapter V; to Dr. E.P. Felt, Entomologist of the State of New York, for suggestions in the preparation of the section of the book relating to insects; to Dr.
W.A. Murrill, a.s.sistant Director of the New York Botanical Gardens, for Fig. 108; and to Mr. Hermann W. Merkel, Chief Forester of the New York Zoological Park, for Figs. 26, 59 and 60.
J.J. LEVISON.
BROOKLYN, N.Y.
June, 1914.
INTRODUCTION
A good many popular books on trees have been published in the United States in recent years. The continually increasing demand for books of this character indicates the growing public interest not only in the trees that we pa.s.s in our daily walks, but also in the forest considered as a community of trees, because of its aesthetic and protective value and its usefulness as a source of important economic products.
As a nation, we are thinking more about trees and woods than we were wont to do in the years gone by. We are growing to love the trees and forests as we turn more and more to outdoor life for recreation and sport. In our ramblings along shady streets, through gra.s.sy parks, over wooded valleys, and in mountain wildernesses we find that much more than formerly we are asking ourselves what are these trees, what are the leaf, flower, twig, wood and habit characteristics which distinguish them from other trees; how large do they grow; under what conditions of soil and climate do they thrive best; what are their enemies and how can they be overcome; what is their value for wood and other useful products; what is their protective value; are they useful for planting along streets and in parks and in regenerating forests; how can the trees of our streets and lawns be preserved and repaired as they begin to fail from old age or other causes? All these questions and many more relating to the important native and exotic trees commonly found in the states east of the Great Lakes and north of Maryland Mr. Levison has briefly answered in this book. The author"s training as a forester and his experience as a professional arboriculturist has peculiarly fitted him to speak in an authoritative and interesting way about trees and woods.
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 cla.s.sifies all related species and distinguishes those that are liable to be confused with the particular tree under consideration.
GROUP I. THE PINES
[Ill.u.s.tration: FIG. 1.--Twig of the Austrian Pine.]
How to tell them from other trees: The pines belong to the _coniferous_ cla.s.s 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.
[Ill.u.s.tration: FIG. 2.--Twig of the White Pine.]
The pines are widely distributed throughout the Northern Hemisphere, and include about 80 distinct species with over 600 varieties. The species enumerated here are especially common in the eastern part of the United states, growing either native in the forest or under cultivation in the parks. The pines form a very important cla.s.s of timber trees, and produce beautiful effects when planted in groups in the parks.
How to tell them from each other: The pine needles are arranged in _cl.u.s.ters_; see Fig. 1. Each species has a certain characteristic number of needles to the cl.u.s.ter and this fact generally provides the simplest and most direct way of distinguishing the different pines.
In the white pine there are _five_ needles to each cl.u.s.ter, in the pitch pine _three_, and in the Scotch pine _two_. The Austrian pine also has two needles to the cl.u.s.ter, but the difference in size and character of the needles will distinguish this species from the Scotch pine.
THE WHITE PINE (_Pinus strobus_)
Distinguishing characters: The tree can be told at close range by the number of needles to each cl.u.s.ter, Fig. 2. There are *five* needles to each cl.u.s.ter of the white pine. They are bluish green, slender, and about four inches in length.
At a distance the tree may be told by the *right angles* which the branches form with the main trunk, Fig. 3. No other pine shows this character.
Form and size: A tall tree, the stateliest of the evergreens.
Range: Eastern North America.
Soil and location: Prefers a deep, sandy soil, but will grow in almost any soil.
Enemies: Sucking insects forming white downy patches on the bark and twigs, the _white pine weevil_, a boring insect, and the _white pine blister rust_, a fungus, are among its princ.i.p.al enemies.
[Ill.u.s.tration: FIG. 3.--The White Pine.]
Value for planting: Aside from its value as an ornamental tree, the white pine is an excellent tree to plant on abandoned farms and for woodlands and windbreaks throughout the New England States, New York, Pennsylvania, and the Lake States.
Commercial value: The wood is easily worked, light, durable, and will not warp. It is used for naval construction, lumber, shingles, laths, interior finish, wooden ware, etc.
Other characters: The _fruit_ is a cone, four to six inches long.
Comparisons: The tree is apt to be confused with the _Bhotan pine_ (_Pinus excelsa_), which is commonly grown as an ornamental tree.