Frontispiece.
“Come forth into the light of things,
Let Nature be your Teacher.”—Wordsworth.
Studies of Trees
by
J. J. Levison, M.F.
Lecturer on Ornamental and Shade Trees, Yale University Forest School;
Forester to the Department of Parks, Brooklyn, N. Y.
First Edition
First Thousand
1914
[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 résumé 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, Assistant 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.
[Contents]
- Chapter I
- [How To Identify Trees]
- Chapter II
- [How To Identify Trees (Continued)]
- Chapter III
- [How To Identify Trees (Continued)]
- Chapter IV
- [The Structure And Requirements Of Trees]
- Chapter V
- [What Trees To Plant And How]
- Chapter VI
- [The Care Of Trees]
- Chapter VII
- [Forestry]
- Chapter VIII
- [Our Common Woods: Their Identification, Properties And Uses]
- Chapter IX
- [An Outdoor Lesson On Trees]
[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 pass in our daily walks, but also in the forest considered as a community of trees, because of its æsthetic 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 grassy 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.
[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]
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.
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 class 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 clusters; see [Fig. 1]. Each species has a certain characteristic number of needles to the cluster 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 cluster, in the pitch pine three, and in the Scotch pine two. The Austrian pine also has two needles to the cluster, 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 cluster, [Fig. 2]. There are five needles to each cluster 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 principal enemies.
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. The Bhotan pine, however, has needles much longer and more drooping in appearance.
The Pitch Pine (Pinus rigida)
Distinguishing characters: Here there are three needles to each cluster, [Fig. 4]. They are dark, yellowish-green needles about four inches long. The rough-looking branches of the tree may be seen studded with cones throughout the year, and clusters of leaves may be seen sprouting directly from the trunk of the tree; see [Fig. 5]. The last two are very characteristic and will distinguish the tree at a glance.
Form and size: It is a low tree of uncertain habit and extremely rough looking at every stage of its life. It is constantly full of dead branches and old cones which persist on the tree throughout the year.
Range: Eastern United States.
Soil and location: Grows in the poorest and sandiest soils where few other trees will grow. In New Jersey and on Long Island where it is native, it proves so hardy and persistent that it often forms pure stands excluding other trees.
Fig. 4.—Twig of the Pitch Pine.
Enemies: None of importance.
Value for planting: Well adapted for the sea coast and other exposed places. It is of extremely uncertain habit and is subject to the loss of the lower limbs. It frequently presents a certain picturesqueness of outline, but it could not be used as a specimen tree on the lawn.
Fig. 5.—The Pitch Pine.
Commercial value: The wood is coarse grained and is used for rough lumber, fuel, and charcoal.
Other characters: The fruit is a cone one to three inches long, persistent on the tree for several years.
The Scotch Pine (Pinus sylvestris)
Distinguishing characters: There are two needles to each cluster, and these are short compared with those of the white pine, and slightly twisted; see [Fig. 6]. The bark, especially along the upper portion of the trunk, is reddish in color.
Form and size: A medium-sized tree with a short crown.
Range: Europe, Asia, and eastern United States.
Soil and location: Will do best on a deep, rich, sandy soil, but will also grow on a dry, porous soil.
Enemies: In Europe the Scotch pine has several insect enemies, but in America it appears to be free from injury.
Value for planting: Suitable for windbreaks and woodland planting. Many excellent specimens may also be found in our parks.
Commercial value: In the United States, the wood is chiefly used for fuel, though slightly used for barrels, boxes, and carpentry. In Europe, the Scotch pine is an important timber tree.
Comparisons: The Scotch pine is apt to be confused with the Austrian pine (Pinus austriaca), because they both have two needles to each cluster. The needles of the Austrian pine, however, are much longer, coarser, straighter, and darker than those of the Scotch pine; [Fig. 1]. The form of the Austrian pine, too, is more symmetrical and compact.
Fig. 6.—Twig of the Scotch Pine.
The red pine (Pinus resinosa) is another tree that has two needles to each cluster, but these are much longer than those of the Scotch pine (five to six inches) and are straighter. The bark, which is reddish in color, also differentiates the red pine from the Austrian pine. The position of the cones on the red pine, which point outward and downward at maturity, will also help to distinguish this tree from the Scotch and the Austrian varieties.
[Group II. The Spruce and Hemlock]
How to tell them from other trees: The spruce and hemlock belong to the evergreen class and may be told from the other trees by their leaves. The characteristic leaves of the spruce are shown in Fig. 9; those of the hemlock in [Fig. 10]. These are much shorter than the needles of the pines but are longer than the leaves of the red cedar or arbor vitae. They are neither arranged in clusters like those of the larch, nor in feathery layers like those of the cypress. They adhere to the tree throughout the year, while the leaves of the larch and cypress shed in the fall.
The spruces are pyramidal-shaped trees, with tall and tapering trunks, thickly covered with branches, forming a compact crown. They are widely distributed throughout the cold and temperate regions of the northern hemisphere, where they often form thick forests over extended areas.
There are eighteen recognized species of spruce. The Norway spruce has been chosen as a type for this group because it is so commonly planted in the northeastern part of the United States.
The hemlock is represented by seven species, confined to temperate North America, Japan, and Central and Western China.
Fig. 7.—The Norway Spruce.
How to tell them from each other: The needles and branches of the spruce are coarse; those of the hemlock are flat and graceful. The individual leaves of the spruce, [Fig. 9], are four-sided and green or blue on the under side, while those of the hemlock, [Fig. 10], are flat and are marked by two white lines on the under side.
The Norway Spruce (Picea excelsa)
Distinguishing characters: The characteristic appearance of the full-grown tree is due to the drooping branchlets carried on main branches which bend upward ([Fig. 7]).
Leaf: The leaves are dark green in color and are arranged spirally, thus making the twigs coarser to the touch than the twigs of the hemlock or fir. In cross-section, the individual leaflet is quadrilateral, while that of the pine is triangular.
Form and size: A large tree with a straight, undivided trunk and a well-shaped, conical crown ([Fig. 7]).
Range: Northern Europe, Asia, northern North America.
Soil and location: Grows in cool, moist situations.
Enemies: The foliage of the spruce is sometimes affected by red spider, but is apt to be more seriously injured by drought, wind, and late frosts.
Value for planting: Commonly planted as an ornamental tree and for hedges. It does well for this purpose in a cool northern climate, but in the vicinity of New York City and further south it does not do as well, losing its lower branches at an early age, and becoming generally scraggly in appearance.
Fig. 8.—A Group of Hemlock.
Commercial value: The wood is light and soft and is used for construction timber, paper pulp, and fuel.
Other characters: The fruit is a large slender cone, four to seven inches long.
Comparisons: The white spruce (Picea canadensis) may be told from the Norway spruce by the whitish color on the under side of its leaves and the unpleasant, pungent odor emitted from the needles when bruised. The cones of the white spruce, about two inches long, are shorter than these of the Norway spruce, but are longer than those of the black spruce.
It is essentially a northern tree growing in all sorts of locations along the streams and on rocky mountain slopes as far north as the Arctic Sea and Alaska. It often appears as an ornamental tree as far south as New York and Pennsylvania.
The black spruce (Picea mariana) may be told from the other spruces by its small cone, which is usually only about one inch in length. In New England it seldom grows to as large a size as the other spruce trees.
It covers large areas in various parts of northern North America and grows to its largest size in Manitoba. The black spruce has little value as an ornamental tree.
The Colorado blue spruce (Picea parryana or Picea pungens) which is commonly used as an ornamental tree on lawns and in parks, can be told from the other spruces by its pale-blue or sage-green color and its sharp-pointed, coarse-feeling twigs. Its small size and sharp-pointed conical form are also characteristic.
It grows to a large size in Colorado and the Middle West. In the Eastern States and in northern Europe where it is planted as an ornamental tree, it is usually much smaller.
Fig. 9.—Twig of the Norway Spruce.
Hemlock (Tsuga canadensis)
Distinguishing characters: Its leaves are arranged in flat layers, giving a flat, horizontal and graceful appearance to the whole branch ([Fig. 8]). The individual leaves are dark green above, lighter colored below, and are marked by two white lines on the under side ([Fig. 10]).
The leaves are arranged on little stalks, a characteristic that does not appear in the other evergreen trees.
Form and size: A large tree with a broad-based pyramidal head, and a trunk conspicuously tapering toward the apex. The branches extend almost to the ground.
Range: The hemlock is a northern tree, growing in Canada and the United States.
Soil and location: Grows on all sorts of soils, in the deepest woods as well as on high mountain slopes.
Enemies: None of importance.
Value for planting: The hemlock makes an excellent hedge because it retains its lowest branches and will stand shearing. In this respect it is preferable to the spruce. It makes a fair tree for the lawn and is especially desirable for underplanting in woodlands, where the shade from the surrounding trees is heavy. In this respect it is like the beech.
Commercial value: The wood is soft, brittle, and coarse-grained, and is therefore used mainly for coarse lumber. Its bark is so rich in tannin that it forms one of the chief commercial products of the tree.
Other characters: The fruit is a small cone about ¾ of an inch long, which generally hangs on the tree all winter.
Fig. 10.—Twig of the Hemlock.
[Group III. The Red Cedar and Arbor-Vitae]
How to tell them from other trees: The red cedar (juniper) and arbor-vitae may be told from other trees by their leaves, which remain on the tree and keep green throughout the entire year. These leaves differ from those of the other evergreens in being much shorter and of a distinctive shape as shown in Figs. [12] and [13]. The trees themselves are much smaller than the other evergreens enumerated in this book. Altogether, there are thirty-five species of juniper recognized and four of arbor-vitae. The junipers are widely distributed over the northern hemisphere, from the Arctic region down to Mexico in the New World, and in northern Africa, China, and Japan in the Old World. The arbor-vitae is found in northeastern and northwestern America, China, and Japan. The species mentioned here are those commonly found in America.
How to tell them from each other: The twigs of the arbor-vitae are flat and fan-like as in [Fig. 13]; the twigs of the red cedar are needle-shaped or scale-like as in [Fig. 12]. The foliage of the arbor-vitae is of a lighter color than that of the red cedar, which is sombre green. The arbor-vitae will generally be found growing in moist locations, while the red cedar will grow in dry places as well. The arbor-vitae generally retains its lower branches in open places, while the branches of the red cedar start at some distance from the ground.
Red Cedar (Juniperus virginiana)
Fig. 11.—The Red Cedar.
Distinguishing characters: The tree can best be told at a glance by its general form, size and leaves. It is a medium-sized tree with a symmetrical, cone-like form, [Fig. 11], which, however, broadens out somewhat when the tree grows old. Its color throughout the year is dull green with a tinge of brownish red, and its bark peels in thin strips.
Fig. 12(a).—Twig of Young Cedar.
Fig. 12(b).—Twig of Cedar (Older Tree).
Leaf: In young trees the leaf is needle-shaped, pointed, and marked by a white line on its under side, [Fig. 12(a)]. In older trees it is scale-like, [Fig. 12(b)], and the white line on its under side is indistinct.
Range: Widely distributed over nearly all of eastern and central North America.
Soil and location: Grows on poor, gravelly soils as well as in rich bottom lands.
Enemies: The “cedar apple,” commonly found on this tree, represents a stage of the apple rust, and for that reason it is not desirable to plant such trees near orchards. Its wood is also sometimes attacked by small boring insects.
Value for planting: Its characteristic slender form gives the red cedar an important place as an ornamental tree, but its chief value lies in its commercial use.
Commercial value: The wood is durable, light, smooth and fragrant, and is therefore used for making lead-pencils, cabinets, boxes, moth-proof chests, shingles, posts, and telegraph poles.
Other characters: The fruit is small, round and berry-like, about the size of a pea, of dark blue color, and carries from one to four bony seeds.
Other common names: The red cedar is also often called juniper and red juniper.
Comparisons: The red cedar is apt to be confused with the low juniper (Juniperus communis) which grows in open fields all over the world. The latter, however, is generally of a low form with a flat top. Its leaves are pointed and prickly, never scale-like, and they are whitish above and green below. Its bark shreds and its fruit is a small round berry of agreeable aromatic odor.
Arbor-Vitae; Northern White Cedar (Thuja occidentalis)
Distinguishing characters: The branchlets are extremely flat and fan-like, [Fig. 13], and have an agreeable aromatic odor when bruised. The tree is an evergreen with a narrow conical form.
Fig. 13.—Twig of the Arbor-Vitae.
Leaf: Leaves of two kinds, one scale-like and flat, the other keeled, all tightly pressed to the twig (see [Fig. 13]).
Form and size: A close, conical head with dense foliage near the base. Usually a small tree, but in some parts of the northeastern States it grows to medium size with a diameter of two feet.
Range: Northern part of North America.
Soil and location: Inhabits low, swampy lands; in the State of Maine often forming thick forests.
Enemies: Very seldom affected by insects.
Value for planting: Is hardy in New England, where it is especially used for hedges. It is also frequently used as a specimen tree on the lawn.
Commercial value: The wood is durable for posts, ties, and shingles. The bark contains considerable tannin and the juices from the tree have a medicinal value.
Other characters: The fruit is a cone about ½ inch long.
Other common names: Arbor-vitae is sometimes called white cedar and cedar.
Comparisons: The arbor-vitae is apt to be confused with the true white cedar (Chamæcyparis thyoides) but the leaves of the latter are sharp-pointed and not flattened or fan-shaped.
[Chapter II]
How To Identify Trees—(Continued)
[Group IV. The Larch And Cypress]
How to tell them from other trees: In summer the larch and cypress may easily be told from other trees by their leaves. These are needle-shaped and arranged in clusters with numerous leaves to each cluster in the case of the larch, and feathery and flat in the case of the cypress. In winter, when their leaves have dropped off, the trees can be told by their cones, which adhere to the branches.
There are nine recognized species of larch and two of bald cypress. The larch is characteristically a northern tree, growing in the northern and mountainous regions of the northern hemisphere from the Arctic circle to Pennsylvania in the New World, and in Central Europe, Asia, and Japan in the Old World. It forms large forests in the Alps of Switzerland and France.
The European larch and not the American is the principal species considered here, because it is being planted extensively in this country and in most respects is preferable to the American species.
The bald cypress is a southern tree of ancient origin, the well-known cypress of Montezuma in the gardens of Chepultepec having been a species of Taxodium. The tree is now confined to the swamps and river banks of the South Atlantic and Gulf States, where it often forms extensive forests to the exclusion of all other trees. In those regions along the river swamps, the trees are often submerged for several months of the year.
How to tell them from each other: In summer the larch may be told from the cypress by its leaves (compare Figs. [14] and [16]). In winter the two can be distinguished by their characteristic forms. The larch is a broader tree as compared with the cypress and its form is more conical. The cypress is more slender and it is taller. The two have been grouped together in this study because they are both coniferous trees and, unlike the other Conifers, are both deciduous, their leaves falling in October.
Fig. 14.—Twig of the Larch in Summer.
The European Larch (Larix europaea)
Distinguishing characters: Its leaves, which are needle-shaped and about an inch long, are borne in clusters close to the twig, [Fig. 14]. There are many leaves to each cluster. This characteristic together with the spire-like form of the crown will distinguish the tree at a glance.
Leaf: The leaves are of a light-green color but become darker in the spring and in October turn yellow and drop off. The cypress, which is described below, is another cone-bearing tree which sheds its leaves in winter.
Fig. 15.—Twig of the Larch in Winter.
Form and size: A medium-sized tree with a conical head and a straight and tapering trunk. (See [Fig. 90].)
Range: Central Europe and eastern and central United States.
Soil and location: Requires a deep, fresh, well-drained soil and needs plenty of light. It flourishes in places where our native species would die. Grows very rapidly.
Enemies: The larch is subject to the attacks of a sawfly, which has killed many trees of the American species. A fungus (Trametes pini) which causes the tree to break down with ease is another of its enemies.
Value for planting: A well-formed tree for the lawn. It is also useful for group planting in the forest.
Commercial value: Because its wood is strong and durable the larch is valuable for poles, posts, railroad ties, and in shipbuilding.
Fig. 16.—Twig of the Cypress.
Other characters: The fruit is a small cone about one inch long, adhering to the tree throughout the winter.
Fig. 17.—The Bald Cypress.
Comparisons: The tree is apt to be confused with the American larch, also known as tamarack and hackmatack, but differs from it in having longer leaves, cones twice as large and more abundant and branches which are more pendulous.
The larch differs from the bald cypress in the broader form of its crown and the cluster-like arrangement of its leaves. The twigs of the bald cypress are flat and feathery. The larch and bald cypress have the common characteristics of both shedding their leaves in winter and preferring to grow in moist or swampy soils. The larch, especially the native species, forms the well-known tamarack swamps of the north. The bald cypress grows in a similar way in groups in the southern swamps.
Bald Cypress (Taxodium distichum)
Distinguishing characters: The feathery character of the twigs, Fig. 16, and the spire-like form of the tree, [Fig. 17], which is taller and more slender than the larch, will distinguish this species from others.
Fig. 18.—Cypress “Knees.”
Leaf: The leaves drop off in October, though the tree is of the cone-bearing kind. In this respect it is like the larch.
Form and size: Tall and pyramidal.
Range: The cypress is a southern tree, but is found under cultivation in parks and on lawns in northern United States.
Soil and location: Grows naturally in swamps, but will also do well in ordinary well-drained, good soil. In its natural habitat it sends out special roots above water. These are known as “cypress knees” ([Fig. 18]) and serve to provide air to the submerged roots of the tree.
Enemies: None of importance.
Value for planting: An excellent tree for park and lawn planting.
Commercial value: The wood is light, soft, and easily worked. It is used for general construction, interior finish, railroad ties, posts and cooperage.
Other characters: The bark is thin and scaly. The fruit is a cone about an inch in diameter. The general color of the tree is a dull, deep green which, however, turns orange brown in the fall.
Comparisons: The cypress and the larch are apt to be confused, especially in the winter, when the leaves of both have dropped. The cypress is more slender and is taller in form. The leaves of each are very different, as will be seen from the accompanying illustrations.
[Group V. The Horsechestnut, Ash and Maple]
How to tell them from other trees: The horsechestnut, ash, and maple have their branches and buds arranged on their stems opposite each other as shown in Figs. [20], [22] and [24]. In other trees, this arrangement is alternate, as shown in [Fig. 19].
How to tell these three from each other. If the bud is large—an inch to an inch and a half long—dark brown, and sticky, it is a horsechestnut.
If the bud is not sticky, much smaller, and rusty brown to black in color, and the ultimate twigs, of an olive green color, are flattened at points below the buds, it is an ash.
Fig. 19.—Alternate Branching (Beech.)
If it is not a horsechestnut nor an ash and its small buds have many scales covering them, the specimen with branches and buds opposite must then be a maple. Each of the maples has one character which distinguishes it from all the other maples. For the sugar maple, this distinguishing character is the sharp point of the bud. For the silver maple it is the bend in the terminal twig. For the red maple it is the smooth gray-colored bark. For the Norway maple it is the reddish brown color of the full, round bud, and for the box elder it is the greenish color of its terminal twig.
The form of the tree and the leaves are also characteristic in each of the maples, but for the beginner who does not wish to be burdened with too many of these facts at one time, those just enumerated will be found most certain and most easily followed.
Fig. 20.—Opposite Branching (Horsechestnut.)
The Horsechestnut (Æsculus hippocastanum)
Distinguishing characters: The sticky nature of the terminal bud and its large size (about an inch long). The bud is dark brown in color. See [Fig. 20].
Leaf: Five to seven leaflets, usually seven. [Fig. 21].
Form and size: Medium-sized tree, pyramidal head and coarse twigs.
Range: Europe and eastern United States.
Soil and location: Prefers a deep, rich soil.
Enemies: The leaves are the favorite food of caterpillars and are subject to a blight which turns them brown prematurely. The trunk is often attacked by a disease which causes the flow of a slimy substance.
Value for planting: On account of its showy flowers, the horsechestnut is a favorite for the park and lawn.
Commercial value: The wood is not durable and is not used commercially.
Other characters: The flowers appear in large white clusters in May and June. The fruit is large, round, and prickly.
Fig. 21.—Leaf of the Horsechestnut.
Comparisons: The red horsechestnut differs from this tree in having red flowers. The buckeye is similar to the horsechestnut, but its bud is not sticky and is of a lighter gray color, while the leaf generally has only five leaflets.
The White Ash (Fraxinus americana)
Distinguishing characters: The terminal twigs of glossy olive green color are flattened below the bud. [Fig. 22]. The bud is rusty-brown.
Fig. 22.—Twig of White Ash.
Leaf: Five to nine leaflets. [Fig. 23].
Form and size: A large tree with a straight trunk.
Range: Eastern North America.
Soil and location: Rich, moist soil.
Enemies: In cities it is very often attacked by sucking insects.
Value for planting: The white ash grows rapidly. On account of its insect enemies in cities, it should be used more for forest planting and only occasionally for ornament.
Commercial value: It has a heavy, tough, and strong wood, which is valuable in the manufacture of cooperage stock, agricultural implements, and carriages. It is superior in value to the black ash.
Other characters: The bark is gray. The flowers appear in May.
Comparisons: The white ash is apt to be confused with the black ash (Fraxinus nigra), but differs from the latter in having a lighter-colored bud. The bud of the black ash is black. The bark of the white ash is darker in color and the terminal twigs are more flattened than those of the black ash.
Fig. 23.—Leaf of White Ash.
Sugar Maple (Acer saccharum)
Distinguishing characters: The bud is sharp-pointed, scaly, and reddish brown. [Fig. 24].
Fig. 24.—Twig of the Sugar Maple.
Leaf: Has sharp points and round sinus. [Fig. 25].
Form and size: The crown is oval when the tree is young and round in old age. [Fig. 26].
Range: Eastern United States.
Soil and location: Moist and deep soil, and cool, shady positions.
Enemies: Subject to drouth, especially in cities. Is attacked by the sugar maple borer and the maple phenacoccus, a sucking insect.
Value for planting: Its rich and yellow color in the fall, and the fine spread of its crown make it a desirable tree for the lawn, especially in the country.
Commercial value: Its wood is hard and takes a good polish; used for interior finish and furniture. The tree is also the source of maple sugar. [Fig. 27].
Other characters: The bark is smooth in young trees and in old trees it shags in large plates. The flowers appear in the early part of April.
Other common names: The sugar maple is sometimes called rock maple or hard maple.
Silver Maple (Acer saccharinum)
Distinguishing characters: The tips of the twigs curve upwards (Fig. 28), the bark is scaly, and the leaves are very deeply cleft and are silvery on the under side.
Fig. 25.—Leaf of Sugar Maple.
Leaf: Deeply cleft and silvery under side. [Fig. 29].
Form and size: A large tree with the main branches separating from the trunk a few feet from the ground. The terminal twigs are long, slender, and drooping.
Soil and location: Moist places.
Enemies: The leopard moth, a wood-boring insect, and the cottony-maple scale, a sucking insect.
Fig. 26.—The Sugar Maple.
Value for planting: Grows too rapidly and is too short-lived to be durable.
Commercial value: Its wood is soft, weak, and little used.
Other characters: The bark is light gray, smooth at first and scaly later on. The scales are free at each end and attached in the center. The flowers appear before the leaves in the latter part of March or early April.
Fig. 27.—Tapping the Sugar Maple.
Other common names: The silver maple is sometimes known as soft maple or white maple.
Red Maple (Acer rubrum)
Fig. 28.—Terminal Twig of Silver Maple.
Distinguishing characters: The bark is smooth and light gray, like that of the beech, on the upper branches in older trees, and in young trees over the whole trunk. [Fig. 30]. The buds are in clusters, and the terminal twigs, [Fig. 31], are quite red.
Fig. 29.—Leaf of the Silver Maple.
Leaf: Whitish underneath with three-pointed lobes. [Fig. 32].
Form and size: A medium-sized tree with a narrow, round head.
Range: Eastern North America.
Soil and location: Prefers moist places.