TREES WE KNOW BY THEIR BARK
Hunters and foresters who spend much of their time in the woods learn to know trees by name through long acquaintance. In the dead of winter, the framework of a tree may be enough to recognise it by. Where trees are crowded, this sign is not to be depended upon. The bark is often a guide to the tree’s name. The forester will tell you that the bud is the surest sign of all. The bark is one of the best signs.
It is not the easiest thing in the world to learn to know trees by the bark alone. To the beginner, so many trees with dark, furrowed bark look strangely alike, although the trees are not even related to each other. The foresters began with trees that have peculiar and easily recognised bark. So we shall begin here, and hope that the hard cases will gradually become easier.
Every tree wears a garment of bark from the ground up to the utmost twigs. The thinnest bark is on the youngest branches. The thickest is on the trunk.
Begin with the white birch upon the lawn. The bark of this tree is made of thin layers; the outer one shining like white satin. It breaks and tatters, and peels off around the trunk. Three-cornered patches of black are found under each branch, and others on the trunk show where branches once came out, but were broken or cut off.
Do you notice narrow, horizontal slits of different lengths on the birch bark? These are breathing holes that let the air in to the layer under the bark. Spongy, porous substance fills these slits, but allows the air to pass through. At the lower part of the trunk the satiny outer bark is shed, leaving dark under layers, rough and checked into irregular blocks. As the tree grows older, the trunk becomes rougher and darker, but the branches always show the kind of bark that the little tree wore.
In the Northern woods the white bark of the canoe birch is stripped from the trees in layers as thick as sole leather. Out of these the Indians once made their bark canoes. Now the same material is used for making all manner of trifling souvenirs to sell to tourists. A square of this thick bark, cut on the smooth side of a trunk, may be split into a great number of thin sheets. This the camper uses to write letters upon, and it is a beautiful and fitting substitute for note paper, when one is camping out.
We recognize birches by their silky, tattered bark
The beech trunk is clothed in smooth, pale grey bark
It is a great pity that so many beautiful trees are girdled and killed to supply the needs of camping parties. If the bark were stripped but part way around it would not kill the tree.
The yellow birch has a silvery yellow tint in the outer bark, which curls back in ragged ribbons until the tree gets old. The red birch writes its name in the rusty red colour of its papery bark, which splits into tatters in true birch fashion, and flutters the ragged ends from each branch throughout the year. The black birch has no tattered ribbons flying, but wears a close, smooth, black bark, with the narrow slits that all birches show. As the trunks grow larger the surface checks into irregular plates, separated by furrows. It is called the cherry birch, for the bark is like that of cherry trees.
The sycamore has bark which is different from that of every other tree. Indeed, it is by the bark that we recognise this tree. The tall trunk looks as if it were blotched and streaked and spattered with whitewash, from the trunk to the topmost limb. The bark is continually dropping off in thin, irregular plates, leaving smooth whitish patches of an under layer exposed. After sycamore trees grow older, the bark of the lower portion of the trunk stops shedding. Fine-checked plates of rusty brown cover this oldest portion. But even on the oldest and largest trees, the pale blotches are seen in the branches and we shall never mistake the name of the tree.
The shagbark is one of the rugged and shaggy trees that boys find hard to climb without tearing their clothes into tatters. The bark gives the tree its name. Thin, narrow plates, close-woven and tough as sole leather, seem to be attached very loosely to the body of the tree, but if you try to pull off these narrow strips, you find their hold is very firm. Often they are attached at the middle, and spring out at both ends.
An old shagbark tree is a picturesque figure, as it lifts its bare arms up toward the wintry sky. The trunk is straight, but the branches are full of angles. Yet, with all their rigidity, these limbs have an expression of strength, if not of grace, and the tree’s head is usually symmetrical, and always full of character.
A young hickory has smooth, close-knit bark like that on the branches of the older trees. Gradually the growing trunk becomes furrowed, and the peculiar splintering and splitting of the bark is seen only in trees six inches or more in diameter. By the time the tree is old enough to bear nuts, it has built itself a formidable fence that boys must climb over with much hard work and many a scratch, to get up among the branches and shake down the nuts.
The loose, stripping bark gives its name to the shagbark hickory
Left: Warty bark of hackberry
Center: Silky bark of black birch
Right: Close, sinewy bark of hornbeam
The tasteless pignuts grow on a smooth-barked hickory tree, very easy to climb, but the bark of the little shellbark hickory is the guide-post that leads to the trees where the sweet-flavoured hickory nuts grow.
The close-knit, grey bark of beech trees hardly needs to be described. The temptation to cut initials on beech trunks is more than folks with pocket-knives can resist. No matter how many fine trees there are in a beech grove near town, they are scarred all over with letters and hieroglyphics as far as hand can reach. The tree never covers these wounds. Though they do not cripple it, they mar its beauty painfully.
A little further from the haunts of picnic parties, we shall come upon beech woods that have not thus been abused by thoughtless jack-knives. From the ground, far up into the high tops, a close, beautiful garment of ashy grey bark clothes the tree. Saplings of all ages grow up among the big trees, for beeches grow in colonies. A soft radiance from these many pale tree trunks seems to lighten the woods paths, overshadowed by the dense foliage of the tree tops.
It is said that beech trees die when they come into contact with civilisation. Fine beech woods are included in additions to towns; you will see the great trees die when lawns and gardens are made about their roots. In the outskirts of Indianapolis there are noble beech trees, but they are dying, as the city grows around them.
The copper beeches and the cut-leaved and weeping beeches have the same close-knit bark as our native tree, but it is not grey, but dark brown. These fancy forms are varieties of the European beech, one of the principal lumber trees of the Old World.
The bark of this tree played an interesting part in the early history of the human race. Long before the European tribes had written languages, they sent messages from one to another. These messages between tribes, friendly or warlike, were written in hieroglyphics, cut into the smooth surface of beech bark, and messengers carried them back and forth.
Sheets of beech bark, as well as birch, made the walls and roofs of the huts in which people lived. Their boats and various household utensils were made out of beech wood, which is so close-grained that vessels made of it hold water without leaking.
Another American tree with bark like the beech, but darker grey, grows always, by preference, with its roots in wet soil. It is a little tree, with rigid, horizontal twigs, that form a flat tree top. This is called the blue beech, and its trunk does often have a bluish cast. It is also called hornbeam, for its wood is so hard that it was used in the early days to make the beams which went across the horns of the oxen. This is the part of the ox yoke which is the most subject to wear. Ironwood is another name that describes the hard wood.
We shall notice that this tree has not a regular cylindrical trunk like that of a beech. Strong swellings, that look like muscles, are seen, especially where the trunk branches into the main limbs. Have you ever noticed the arms of a blacksmith, or of an athlete? How the veins and muscles stand out when the arm is in use! Just like them are the irregular swellings that course up the trunk of the hornbeam, and out into the limbs.
The hackberry is a handsome shade tree, which might, at first glance, be mistaken for an elm. The bark is different from that of any other tree. Once we see a hackberry, and learn its name, we will never mistake it again. The bark is light brown or grey, and finely checked by deep furrows. The ridges between bear strange, warty outgrowths. Look for these warts among the small branches. The twigs are smooth, but back a little way the warty eruptions begin, and become more prominent as the limbs thicken and approach the trunk. Sometimes the limbs have these warts so close together as to form continuous ridges.
Another tree with warty bark is the sweet gum. The negroes of the South call the tree “alligator wood,” because the lower part of the trunk is broken by furrows and cross-furrows into horny plates like the skin of an alligator. From the red-brown trunk up into the grey branches, there is a change in the character of the bark. The fissures usually run lengthwise, and the bark rises in thin ridges on each side of the fissure. These ridges become thin as knife blades on the smaller twigs, which also have a sprinkling of small warts.
A sweet gum is very rugged looking in the dead of winter, with its warts and ridges breaking out on each limb. We know it by this sign alone, but are doubly sure when we see the seed balls dangling from the twigs. The sycamore, blotched with white on trunk and limb, also carries a load of dangling seed balls throughout the winter. There is no danger of confusing these two trees, for the bark of each is so distinct.
Warty, ridged bark of the sweet gum, the swinging seed balls and winged seeds
Blotched bark of sycamore, and its seed balls that hang all winter
A little tree with alligator skin bark grows North and South, and chiefly in the eastern half of the country. This is the flowering dogwood, whose grey bark breaks into small squarish plates. There is no such ruggedness in its trunk as there is in the sweet gum’s, for it is always a little tree, and the bark corresponds in its checking to the tree’s size. When we see this peculiar type of bark in the winter woods we may look also for little flattened, box-like flower buds, each enclosed in four scales. We shall also find the twigs set opposite, and with these three signs be sure we know the tree.
A little tree, no larger in girth than the dogwood, but often taller, has bark that strips and loosens somewhat as the bark of the shagbark hickory does. This is the hop hornbeam, one of the ironwoods. Its bark strips are always thin and narrow, no matter how old the tree becomes. It is never as loose upon the trunk as the shagbark’s. The great buds and stout twigs of the hickory are entirely different from the slender spray and the very small buds this ironwood wears in winter. We may find on these twigs some remnant of the hop-like seed clusters which give this little tree its name, hop hornbeam. Inside its shaggy bark the lumbermen find wood so hard that it is very difficult to work, and when made into tools it lasts almost forever.
When we have learned to know at sight a dozen trees by their bark alone, we are ready to go further. A great many trees with furrowed bark like chestnuts and elms and maples, are not so distinct as those already learned, and we must study the tree’s form, its winter buds, the arrangement of these buds, and the shape of the leaf scars in connection with the bark, in order to be sure we know the tree’s name. The chestnut from which we gathered so many nuts last fall, and whose furrowed trunk we saw at every visit, we come to know through this familiarity. The trunks of other chestnut trees look like this one, and though we may not know just how we do it, we have added the chestnut to the list of trees we recognise by their bark alone. The sugar maples which we tap in spring for their sugary sap, have dark, furrowed bark, not very distinctive. And yet, by going from tree to tree, emptying the sap pails, we gradually learn to recognise the bark of the sugar maple, and add it to our growing list.
The Lombardy poplar stands like an exclamation point in the landscape
The live oak of the South is usually hung with long skeins of the weird, grey Spanish moss
Trees do not change their clothes, and they do not move away. Day after day, if we use our eyes and notice what is going on in the tree tops, as the seasons follow each other, we come to know our trees by name; we recognise them in winter by their bark, and by the framework of their tops, in summer by leaves and flowers, in autumn by their changing colour and by their fruits. It is not hard work for those who love trees. It is like getting acquainted with other neighbours whom we are glad to count among our friends.