Chapter 10

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.

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.

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.

Other characters: The _fruit_ is a small cone about one inch long, adhering to the tree throughout the winter.

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.

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_.

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.

THE HORSECHESTNUT (_Aesculus 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.

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.

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.

SUGAR MAPLE (_Acer saccharum_)

Distinguishing characters: The *bud is sharp-pointed*, scaly, and reddish brown. Fig. 24.

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.

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.

Range: Eastern United States.

Soil and location: Moist places.

Enemies: The _leopard moth_, a wood-boring insect, and the _cottony-maple scale_, a sucking insect.

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.

Other common names: The silver maple is sometimes known as _soft maple_ or _white maple_.

RED MAPLE (_Acer rubrum_)

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.

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.

Enemies: Leaf blotches (_Rhytisma acerinum_) which, however, are not very injurious.

Value for planting: Suitable as a shade tree for suburban streets. Its rich red leaves in the fall make it attractive for the lawn.

Commercial value: Its wood is heavy, close-grained, and takes a good polish. Used for furniture and fuel.

Other characters: The _bud_ is small, round, and red. The _flowers_ appear before the leaves are out in the early part of April.

Other common names: The red maple is sometimes known as _swamp maple_.

Comparisons: The red maple is apt to be confused with the silver maple, but the latter can be distinguished by its turned-up twigs and scaly bark over the whole trunk of the tree, which presents a sharp contrast to the straight twig and smooth bark of the red maple. The latter has a bark similar to the beech, but its branches are _opposite_, while those of the beech are _alternate_.

NORWAY MAPLE (_Acer platanoides_)

Distinguishing characters: The bud, Fig. 33, is *oval and reddish-brown* in color; when taken off, a *milky juice exudes*. The bark is close. Fig. 34

Leaf: Like the leaf of the sugar maple but thicker in texture and darker in color. Fig. 35.

Form and size: A tall tree with a broad, round head.

Range: Europe and the United States.

Soil and location: Will grow in poor soil.

Enemies: Very few.

Value for planting: One of the best shade trees.

Commercial value: None.

Other characters: The _bark_ is close like that of the mockernut hickory.

Comparisons: The Norway maple is apt to be confused with the _sycamore maple_ (_Acer pseudoplatanus_), but differs from the latter in having a reddish bud instead of a green bud, and a close bark instead of a scaly bark.

BOX ELDER (_Acer negundo_)

Distinguishing characters: The terminal *twigs are green*, and the buds are round and small. Fig. 36.

Leaf: Has three to seven leaflets.

Form and size: A medium-sized tree with a short trunk and wide-spreading top.

Range: Eastern United States to the Rocky Mountains.

Soil and location: Grows rapidly in deep, moist soil and river valleys, but accommodates itself to the dry and poor soil conditions of the city.

Enemies: Few.

Value for planting: Used as a shade tree in the Middle West, but the tree is so ill formed and so short-lived that it is not to be recommended.

Commercial value: None. The wood is soft.

Other characters: The _bark_ of the trunk is smooth and yellowish-green in young trees and grayish brown in older specimens. The _flowers_ appear in the early part of April. The _fruit_ takes the form of yellowish-green keys which hang on the tree till late fall.

Other common names: The box elder is also commonly known as the _ash-leaf maple_.

GROUP VI. TREES TOLD BY THEIR FORM: ELM, POPLAR, GINGKO AND WILLOW

How to tell them from other trees: The trees described in this group are so distinctive in their general _form_ that they may, for the purpose of study, be grouped together, and distinguished from all other trees by this characteristic.

How to tell them from each other: The American elm is _vase-like_ in shape; the Lombardy poplar is narrow and _spire-like_; the gingko, or maidenhair tree, is _odd_ in its mode of _branching_; and the weeping willow is extremely _pendulous_.

AMERICAN ELM (_Ulmus americana_)

Distinguishing characters: The tree can be told at a glance by its general branching habit. The limbs arch out into a wide-spreading *fan or vase-like crown* which loses itself in numerous fine drooping branchlets. See Fig. 37.

Leaf: The leaves are simple, alternate, and from 2 to 5 inches long.

Form and size: It is a tall tree with a trunk that divides a short distance above ground. Its general contour, together with the numerous branches that interlace its massive crown, give the elm an interesting and stately appearance which is unequaled by any other tree.

Range: Eastern North America.

Soil and location: The elm prefers a deep, rich and moist soil, but will adapt itself even to the poor soil of the city street.

Enemies: _The leopard moth_, a wood-boring insect, and the _elm leaf beetle_, a leaf-eating insect, are the two most important enemies of the tree. Their ravages are very extensive.

Value for planting: The tree has a character of its own which cannot be duplicated for avenue or lawn planting.

Commercial value: The wood is strong and tough and therefore has a special value for cooperage, agricultural implements, carriages, and shipbuilding.

Other characters: The _buds_ are small, brown, and smooth, while those of the European elms are covered with down. The _small side twigs_ come out at almost right angles to the larger terminal twigs, which is not the case in other species of elm.

Other common names: _White elm_.

Comparisons: The _English elm_ (_Ulmus campestris_) is also a tall, dignified tree commonly seen under cultivation in America, but may be told from the American species by the difference in their general contour. The branches of the English species spread out but do not arch like those of the American elm, and the bark of the English elm is darker and coarser, Fig. 38. Little tufts of dead twigs along the main branches and trunk of the tree are characteristic of the English elm and will frequently help to distinguish it from the American elm.

The _Camperdown elm_ may be recognized readily by its dwarf size and its low drooping umbrella-shaped crown.

LOMBARDY OR ITALIAN POPLAR (_Populus nigra, var. italica_)

Distinguishing characters: Its *tall, slender, spire-like form* and rigidly *erect branches*, which commence low on the trunk, make this tree very distinct at all seasons of the year. See Fig. 39.

Leaf: Triangular in shape, similar to that of the Carolina poplar but smaller, see Fig. 40.

Range: Asia, Europe, and North America.

Soil and location: The poplar is easily grown in poor soil, in any location, and is very hardy.

Value for planting: The tree has a distinctive form which makes it valuable for special landscape effects. It is also used for shelter belts and screening. Like all poplars it is short lived and will stand pruning well.

Commercial value: None.

Comparisons: The _Carolina poplar_, or Cottonwood (_Populus deltoides_) can be told from the Lombardy poplar by its wider crown and its more open branching, Fig. 41. It may be recognized by its big terminal twigs, which are light yellow in color and coarser than those of the Lombardy poplar, Fig. 42. Its bark is smooth, light and yellowish-green in young trees, and dark gray and fissured in older specimens. Its large, conical, glossy, chestnut-brown bud is also characteristic, Fig. 42. Its flowers, in the form of large catkins, a peculiarity of all poplars, appear in the early spring. The Carolina poplar is commonly planted in cities because it grows rapidly and is able to withstand the smoke and drouth conditions of the city. Where other trees, however, can be substituted with success, the poplar should be avoided. Its very fast growth is really a point against the tree, because it grows so fast that it becomes too tall for surrounding property, and its wood being extremely soft and brittle, the tree frequently breaks in windstorms. In many cases it is entirely uprooted, because it is not a deep-rooted tree. Its larger roots, which spread near the surface, upset the sidewalk or prevent the growth of other vegetation on the lawn, while its finer rootlets, in their eager search for moisture, penetrate and clog the joints of neighboring water and sewer pipes. The tree is commonly attacked by the _oyster-shell scale_, an insect which sucks the sap from its bark and which readily spreads to other more valuable trees like the elm. The female form of this tree is even more objectionable than the male, because in the early spring the former produces an abundance of cotton from its seeds which litters the ground and often makes walking dangerous. The only justification for planting the Carolina poplar is in places where the conditions for tree growth are so poor that nothing else will grow, and in those cases the tree should be cut back periodically in order to keep it from becoming too tall and scraggly. It is also desirable for screening in factory districts and similar situations.

The _silver_ or _white poplar_ (_Populus alba_) may be told from the other poplars by its characteristic smooth, _whitish-green bark_, often spotted with dark blotches, Fig. 43. The _leaves are silvery-white_ and downy on the under side. The twigs are dark green in color and densely covered with a white down. It grows to very large size and forms an irregular, wide-spreading, broad head, which is characteristically different from that of any of the other poplars.

The _quaking aspen_ (_Populus tremuloides_), the _large-toothed aspen_ (_Populus grandidentata_) and the _balsam poplar_ or _balm of Gilead_ (_Populus balsamifera_) are other common members of the poplar group. The quaking aspen may be told by its reddish-brown twigs, narrow sharp-pointed buds, and by its small finely toothed leaves. The large-toothed aspen has thicker and rather downy buds and broader and more widely toothed leaves. The balsam poplar has a large bud thickly covered with a sticky, pungent, gelatinous substance.

GINGKO OR MAIDENHAIR TREE (_Gingko biloba_)

Distinguishing characters: The *peculiar branches* of this tree *emerge upward* from a straight tapering trunk *at an angle of about 45°* and give to the whole tree a striking, Oriental appearance, which is quite different from that of any other tree, Fig. 44.

Leaf: Like that of a leaflet of maidenhair fern, Fig. 45.

Range: A native of northern China and introduced into eastern North America.

Soil and location: The gingko will grow in poor soils.

Enemies: Practically free from insects and disease.

Value for planting: It makes a valuable tree for the street where heavy shade is not the object and forms an excellent wide-spreading specimen tree on the lawn.

Other characters: The _fruit_ consists of a stone covered by sweet, ill-smelling flesh. The tree is dioecious, there being separate male and female trees. The male tree is preferable for planting in order to avoid the disagreeable odor of the fruit which appears on the female trees when about thirty years old. The male tree has a narrower crown than the female tree. The buds (Fig. 46) are very odd and are conspicuous on the tree throughout the winter. The leaves of the gingko shed in the winter. In this respect the tree is like the larch and the bald cypress.

The gingko belongs to the yew family, which is akin to the pine family. It is therefore a very old tree, the remains of the forests of the ancient world. The gingko in its early life is tall and slender with its few branches close to the stem. But after a time the branches loosen up and form a wide-spreading crown. In the Orient it attains enormous proportions and in this country it also grows to a fairly large size when planted on the open lawn or in groups far apart from other trees so that it can have plenty of room to spread. It then produces a picturesque effect of unusual interest.

WEEPING WILLOW (_Salix babylonica_)

Distinguishing characters: All the willows have a single cap-like scale to the bud, and this species has an unusually *drooping mass of slender branchlets* which characterizes the tree from all others, Fig. 47.

Form and size: It grows to large size.

Range: Asia and Europe and naturalized in eastern United States.

Soil and location: Prefers moist places near streams and ponds.

Enemies: None of importance.

Value for planting: The weeping willow has a special ornamental effect in cemeteries and along lakes and river banks in parks.

Commercial value: It is used in the United States for charcoal and for fuel.

Comparisons: The _pussy willow_ (_Salix discolor_) may easily be told from the other willows by its small size; it is often no higher than a tall shrub. Its branches are _reddish green_ and the buds are dark red, smooth and glossy. The predominating color of the twigs and buds in the pussy willow is therefore a shade of _red_, while in the weeping willow it is _yellowish green_.

GROUP VII. TREES TOLD BY THEIR BARK OR TRUNK: SYCAMORE, BIRCH, BEECH, BLUE BEECH, IRONWOOD, AND HACKBERRY

How to tell them from other trees: The _color of the bark or the form of the trunk_ of each of the trees in this group is distinct from that of any other tree.

How to tell them from each other: In the sycamore, the bark is _mottled_; in the white birch, it is _dull white_; in the beech, it is _smooth and gray_; in the hackberry, it is covered with numerous _corky warts_; in the blue beech, the trunk of the tree is _fluted_, as in Fig. 54, and in the ironwood, the bark _peels_ in thin perpendicular strips.

THE SYCAMORE OR PLANE TREE (_Platanus occidentalis_)

Distinguishing characters: The peculiar *mottled appearance* of the *bark* (Fig. 48) in the trunk and large branches is the striking character here. The bark produces this effect by shedding in large, thin, brittle plates. The newly exposed bark is of a yellowish green color which often turns nearly white later on. *Round seed balls*, about an inch in diameter, may be seen hanging on the tree all winter. In this species, the seed balls are usually solitary, while in the Oriental sycamore, a European tree similar to the native one, they appear in clusters of two, or occasionally of three or four. See Fig. 49.

Leaf: The stem of the leaf completely covers the bud. This is a characteristic peculiar to sycamores.

Form and size: A large tree with massive trunk and branches and a broad head.

Range: Eastern and southern United States.

Soil and location: Prefers a deep rich soil, but will adapt itself even to the poor soil of the city street.

Enemies: The sycamore is frequently attacked by a fungus (_Gloeosporium nervisequum_), which curls up the young leaves and kills the tips of the branches. Late frosts also often injure its young twigs. The Oriental sycamore, which is the European species, is more hardy in these respects than the native one and is therefore often chosen as a substitute.

Value for planting: The Occidental sycamore is now planted very little, but the Oriental sycamore is used quite extensively in its place, especially as a shade tree. The Oriental sycamore is superior to the native species in many ways. It is more shapely, faster growing, and hardier than the native one. Both sycamores will bear transplanting and pruning well.

Commercial value: The wood of the sycamore is coarse-grained and hard to work; used occasionally for inside finishing in buildings.

Other names: _Buttonball_, _buttonwood_.

Comparisons: The _Oriental sycamore_ (_Platanus orientalis_) an introduced species, is apt to be confused with the Occidental sycamore, but may be told from the latter by the number of seed balls suspended from the tree. In the case of the Oriental species, the seed balls hang in _pairs_ or (rarely) three or four together. In the Occidental, the seed balls are generally _solitary_ and very rarely in pairs.

GRAY OR WHITE BIRCH (_Betula populifolia_)

Distinguishing characters: The *dull-white color of the bark* on the trunk and the _dark triangular patches below the insertion of the branches_ distinguish this tree; see Fig. 50. The bark of the young trunks and branches is reddish-brown in color and glossy. The bark adheres closely to the trunk of the tree and does not peel in loose, shaggy strips, as in the case of the yellow or golden birch. It is marked by small raised horizontal lines which are the lenticels or breathing pores. These lenticels are characteristic of all birch and cherry trees. In addition to the distinction in the color of the bark, an important character which distinguishes the gray birch from all other species of birch, is found in the *terminal twigs*, which are *rough* to the touch.

Form and size: A small tree. Frequently grows in clumps.

Range: Eastern United States.

Soil and location: The gray birch does best in a deep, rich soil, but will also grow in poor soils.

Enemies: The _bronze-birch borer_, a wood-destroying insect, and _Polyporus betulinus_, a fungus, are its chief enemies.

Value for planting: Its graceful habit and attractive bark gives the tree an important place in ornamental planting. It may be used to advantage with evergreens, and produces a charming effect when planted by itself in clumps.

Commercial value: The wood is soft and not durable. It is used in the manufacture of small articles and for wood pulp.

Other characters: The _fruit is a catkin_.

Comparisons: The _paper birch_ (_Betula papyrifera_) is apt to be confused with the gray birch, because both have a white bark. The bark of the paper birch, however, is a clear white and peels off in thin papery layers instead of being close. It very seldom shows any dark triangular markings on the trunk. Its terminal twigs are not rough and its trunk is usually straighter and freer from branches.

The _black_ or _sweet birch_ (_Betula lenta_) has a bark similar to the gray birch, except that its color is dark gray. See Fig. 51. The twigs have an aromatic taste.

The _yellow birch_ (_Betula lutea_) has a yellowish or golden bark which constantly peels in thin, ragged, horizontal films.

The _European white birch_ (_Betula alba_) has a dull-white bark like the native white birch, but has smooth terminal twigs instead of rough ones. It is commonly seen in the United States on lawns and in parks.

AMERICAN BEECH (_Fagus americana_)

Distinguishing characters: The *close-fitting, smooth, gray bark* will tell this tree from all others except the red maple and yellow-wood. See Fig. 52. The red maple may then be easily eliminated by noting whether the branches are alternate or opposite. They are alternate in the beech and opposite in the maple. The yellow-wood may be eliminated by noting the size of the bud. The *bud* in the yellow-wood is hardly noticeable and of a golden yellow color, while that of the beech is very *long, slender, and sharp-pointed*, and chestnut brown in color. See Fig. 53.

Form and size: It grows tall in the woods, but on the open lawn spreads out into a massive, round-headed tree.

Range: Eastern Canada and United States.

Soil and location: Prefers a rich, well-drained soil, but will grow in any good soil.

Enemies: _Aphides_ or plant lice that suck the sap from the leaves in spring and early summer are the chief enemies of the tree.

Value for planting: The pleasing color of its bark, its fine spread of branches, which gracefully droop down to the ground, and its autumnal coloring, make the beech a favorite for lawn and park planting. The several European species of beech are equally charming.

Commercial value: The wood is strong, close-grained, and tough. It is used mainly for cooperage, tool handles, shoe lasts, chairs, etc., and for fuel.

Other characters: The _fruit_ is a prickly burr encasing a sharply triangular nut which is sweet and edible.

Comparisons: The _European beech_ (_Fagus sylvatica_), and its weeping, purple-leaved, and fern-leaved varieties, are frequently met with in parks and may be told from the native species by its darker bark. The weeping form may, of course, be told readily by its drooping branches. The leaves of the European beeches are broader and less serrated than those of the American beech.

BLUE BEECH OR HORNBEAM (_Carpinus caroliniana_)

Distinguishing characters: The *fluted* or muscular effect of its *trunk* will distinguish the tree at a glance, Fig. 54.

Leaf: Doubly serrated; otherwise the same as that of ironwood.

Form and size: A low-spreading tree with branches arching out at various angles, forming a flattened head with a fine, slender spray.

Range: Very common in the eastern United States.

Soil and location: Grows in low wet woods.

Enemies: None of importance.

Value for planting: Its artistic branching and curious trunk give the tree an important place in park planting.

Commercial value: None.

Other characters: The bark is smooth and bluish gray in color.

Comparisons: The blue beech or hornbeam is often confused with the _ironwood_ or _hop hornbeam_ (_Ostrya virginiana_). The ironwood, however, has a characteristic bark that peels in perpendicular, short, thin segments, often loose at the ends. See Fig. 55. This is entirely different from the close, smooth, and fluted bark of the blue beech. The color of the bark in the ironwood is brownish, while that of the blue beech is bluish-gray. The buds of the ironwood are greenish with brown tips, while the bud of the blue beech shows no green whatever.

HACKBERRY (_Celtis occidentalis_)

Distinguishing characters: The tree may be told readily from other trees by the *corky tubercles* on the bark of the lower portion of the trunk. See Fig. 56.

Leaf: Has three predominating veins and is a bit more developed on one side than on the other.

Form and size: A small or medium-sized tree with a single stem and broad conical crown.

Range: United States and Canada.

Soil and location: Grows naturally in fertile soils, but will adapt itself to almost sterile soils as well.

Enemies: The hackberry is usually free from disease, though often its leaves are covered with insect galls.

Value for planting: It is extensively planted as a shade tree in the Middle West, and is frequently seen as an ornamental tree in the East.

Commercial value: It has little economic value except for fuel.

Other characters: The _fruit_ is berry-like, with a hard pit. The fleshy outer part is sweet.

Other common names: _Nettle tree_; _sugarberry_.

GROUP VIII. THE OAKS AND CHESTNUT

How to tell them from other trees: The oaks are rather difficult to identify and, in studying them it will often be necessary to look for more than one distinguishing character. The oaks differ from other trees in bearing _acorns_. Their _leaves_ have many lobes and their upper lateral _buds_ cluster at the top of the twigs. The general contour of each oak presents a characteristic branching and sturdiness uncommon in other trees.

The chestnut differs from other trees in bearing _burs_ and its _bark_ is also distinctly characteristic.

How to tell them from each other: There are two groups of oaks, the _white oak_ and the _black oak_. The white oaks mature their acorns in one year and, therefore, only acorns of the same year can be found on trees of this group. The black oaks take two years in which to mature their acorns and, therefore, young acorns of the present year and mature acorns of the previous year may be found on the same tree at one time. The _leaves_ of the white oaks have rounded margins and rounded lobes as in Fig. 57, while those of the black oaks have pointed margins and sharp pointed lobes as shown in Figs. 60, 62 and 64. The _bark_ of the white oaks is light colored and breaks up in loose flakes as in Fig. 58, while that of the black oaks is darker and deeply ridged or tight as in Figs. 59 and 61. The white oak is the type of the white oak group and the black, red and pin oaks are types of the other. For the characterization of the individual species, the reader is referred to the following pages.

WHITE OAK (_Quercus alba_)

Distinguishing characters: The massive ramification of its branches is characteristic of this species and often an easy clue to its identification. The *bark* has a *light gray color*--lighter than that of the other oaks--and breaks into soft, loose flakes as in Fig. 58. The *leaves are deeply lobed* as in Fig. 57. The *buds are small, round and congested* at the end of the year's growth. The acorns usually have no stalks and are set in shallow, rough cups. The kernels of the acorns are white and palatable.

Form and size: The white oak grows into a large tree with a wide-spreading, massive crown, dissolving into long, heavy, twisted branches. When grown in the open it possesses a short sturdy trunk; in the forest its trunk is tall and stout.

Range: Eastern North America.

Soil and location: The white oak thrives in almost any well-drained, good, deep soil except in a very cold and wet soil. It requires plenty of light and attains great age.

Enemies: The tree is comparatively free from insects and disease except in districts where the Gipsy moth is common, in which case the leaves of the white oak are a favorite food of its caterpillars.

Value for planting: The white oak is one of the most stately trees. Its massive form and its longevity make the tree suitable for both lawn and woodland planting but it is not used much because it is difficult to transplant and grows rather slowly.

Commercial value: The wood is of great economic importance. It is heavy, hard, strong and durable and is used in cooperage, construction work, interior finish of buildings and for railroad ties, furniture, agricultural implements and fuel.

Comparisons: The _swamp white oak_ (_Quercus platanoides_) is similar to the white oak in general appearance of the bark and form and is therefore liable to be confused with it. It differs from the white oak, however, in possessing a more straggly habit and in the fact that the bark on the under side of its branches shags in loose, large scales. Its buds are smaller, lighter colored and more downy and its acorns are more pointed and with cups more shallow than those of the white oak. The tree also grows in moister ground, generally bordering swamps.

BLACK OAK (_Quercus velutina_)

Distinguishing characters: The *bark* is black, rough and cut up into firm *ridges* especially at the base of the tree, see Fig. 59. The _inner bark_ has a _bright yellow color_: the *leaves* have _sharp points_ and are wider at the base than at the tip as shown in Fig. 60. The buds are _large, downy_ and _sharp pointed_. The acorns are small and have deep, scaly cups the inner margins of which are downy. The kernels are yellow and bitter.

Form and size: The tree grows in an irregular form to large size, with its branches rather slender as compared with the white oak and with a more open and narrow crown.

Range: Eastern North America.

Soil and location: It will grow in poor soils but does best where the soil is rich and well drained.

Enemies: None of importance.

Value for planting: The black oak is the poorest of the oaks for planting and is rarely offered by nurserymen.

Commercial value: The wood is heavy, hard and strong, but checks readily and is coarse grained. It is of little value except for fuel. The bark is used for tannin.

Other common names: _Yellow oak_.

Comparisons: The black oak might sometimes be confused with the _red_ and _scarlet oaks_. The yellow, bitter inner bark will distinguish the black oak from the other two. The light-colored, smooth bark of the red oak and the dark, ridged bark of the black oak will distinguish the two, while the bark of the scarlet oak has an appearance intermediate between the two. The buds of the three species also show marked differences. The buds of the black oak are covered with hairs, those of the scarlet oak have fewer hairs and those of the red are practically free from hairs. The leaves of each of the three species are distinct and the growth habits are different.

RED OAK (_Quercus rubra_)

Distinguishing characters: The *bark* is perpendicularly fissured into long, _smooth, light gray strips_ giving the trunk a characteristic *pillar effect* as in Figs. 61 and 94. It has the straightest trunk of all the oaks. The leaves possess _more lobes_ than the leaves of any of the other species of the black oak group, see Fig. 62. The acorns, the largest among the oaks, are semispherical with the cups extremely shallow. The buds are large and sharp pointed, but not as large as those of the black oak. They also have a few fine hairs on their scales, but are not nearly as downy as those of the Black oak.

Form and size: The red oak is the largest of the oaks and among the largest of the trees in the northern forests. It has a straight trunk, free from branches to a higher point than in the white oak, see Fig. 94. The branches are less twisted and emerge at sharper angles than do those of the white oak.

Range: It grows all over Eastern North America and reaches north farther than any of the other oaks.

Soil and location: It is less fastidious in its soil and moisture requirements than the other oaks and therefore grows in a great variety of soils. It requires plenty of light.

Enemies: Like most of the other oaks, this species is comparatively free from insects and disease.

Value for planting: The red oak grows faster and adapts itself better to poor soil conditions than any of the other oaks and is therefore easy to plant and easy to find in the nurseries. It makes an excellent street tree, is equally desirable for the lawn and is hardly surpassed for woodland planting.

Commercial value: The wood is hard and strong but coarse grained, and is used for construction timber, interior finish and furniture. It is inferior to white oak where strength and durability are required.

PIN OAK (_Quercus palustris_)

Distinguishing characters: Its method of *branching* will characterize the tree at a glance. It develops a well-defined _main_ ascending _stem_ with numerous _drooping_ side _branches_ as in Fig. 63. The buds are very small and sharp pointed and the leaves are small as in Fig. 64. The bark is dark, firm, smooth and in close ridges. The acorn is small and carries a light brown, striped nut, wider than long and bitter. The cup is shallow, enclosing only the base of the nut.

Form and size: The pin oak is a medium-sized tree in comparison with other oaks. It develops a tall, straight trunk that tapers continuously through a pyramidal crown of low, drooping tender, branches.

Range: Eastern North America.

Soil and location: It requires a deep, rich, moist soil and grows naturally near swamps. Its roots are deep and spreading. The tree grows rapidly and is easily transplanted.

Enemies: None of importance.

Value for planting: The pin oak is an extremely graceful tree and is therefore extensively used for planting on lawns and on certain streets where the tree can find plenty of water and where conditions will permit its branches to droop low.

Commercial value: The wood is heavy and hard but coarse grained and liable to check and warp. Its principal use is in the construction of houses and for shingles.

CHESTNUT (_Castanea dentata_)

Distinguishing characters: The *bark* in young trees is smooth and of a marked reddish-bronze color, but when the tree grows older, the bark breaks up into *diamond-shaped ridges*, sufficiently characteristic to distinguish the tree at a glance, see Fig. 65. A close examination of the _terminal twig_ will show _three ridges_ and _two grooves_ running down along the stem from the base of each leaf or leaf-scar. The twig has no true terminal bud. The fruit, a large, round *bur*, prickly without and hairy within and enclosing the familiar dark brown, sweet edible nuts is also a distinguishing mark of the tree.

Leaf: The leaves are distinctly long and narrow. They are from 6 to 8 inches long.

Form and size: The chestnut is a large tree with a massive trunk and broad spreading crown. The chestnut tree when cut, sprouts readily from the stump and therefore in places where the trees have once been cut, a group of two to six trees may be seen emerging from the old stump.

Range: Eastern United States.

Soil and location: It will grow on rocky as well as on fertile soils and requires plenty of light.

Enemies: During the past nine years nearly all the chestnut trees in the United States have been attacked by a fungus disease (_Diaporthe parasitica_, Mur.) which still threatens the entire extinction of the chestnut trees in this country. No remedy has been discovered and all affected trees should be cut down and the wood utilized before it decays and becomes worthless. No species of chestnut tree is entirely immune from this disease, though some species are highly resistant.

Value for planting: The chestnut is one of the most rapidly growing hardwood trees but, on account of its disease, which is now prevalent everywhere, it is not wise to plant chestnut trees for the present.

Commercial value: The wood is light, not very strong and liable to warp. It is durable when brought in contact with the soil and is therefore used for railroad ties, fence-posts, poles, and mine timbers. It is also valuable for interior finish in houses and for fuel. Its bark is used in the manufacture of tanning extracts and the nuts are sold in cities in large quantities.