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.
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 (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.
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.
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.