This tree is known in different regions by the following names: Balsam, balm of Gilead, cottonwood, poplar, balsam poplar, and tacamahac. The usual name, balm of Gilead, is applied in recognition of the supposed healing virtue of the wax which covers the buds and young leaves. It has long been used in medicine, but its exact value is still a matter of discussion. The wild Indians of the North discovered a use for the balsam in mending their bark dishes, and plugging knot holes in the wooden trenchers. The wax is slow to dissolve in water, and it resisted for a long time such soups as were known to the redman"s culinary art.
Bees know the value of the wax and use it to seal cracks and crevices in their hives and to hold the comb in place. It is popularly believed that the economy of the wax on the buds is to keep them from freezing. That view is erroneous, for it would take more than a coating of wax to keep the buds warm with the thermometer from fifty to seventy degrees below zero, as it is every winter in some parts of this tree"s range.
Balm of Gilead is a native of the North from the Atlantic to the Pacific, but its finest growth is about the headwaters of the Mackenzie river, on Peace and Laird rivers, and the lower valley of the Athabaska.
Sixty years ago Sir John Franklin reported that most of the driftwood of the Arctic ocean was this species. Since that time the range has been more definitely determined, and it is now known that the tree grows so far north that it is for some weeks in darkness, and again in summer for some weeks in unbroken sunshine. It grows in Alaska nearly 200 miles north of the Arctic circle. Its natural range southward reaches New England, New York, Michigan, Nebraska, Nevada, and Oregon.
Trees of all sizes abound, from mere shrubs in the outskirts of its range to trunks 100 feet high and six feet in diameter in favored localities. In the United States the best timber seldom exceeds thirty inches in diameter and sixty or seventy feet in height. The bark on limbs and young trunks is brownish-gray, frequently so tinged with green that it is noticeable at a considerable distance; but usually large trees have reddish-gray bark with deep furrows and wide ridges. Year-old twigs are clear, shiny reddish-brown; end buds are about an inch long, the side buds somewhat shorter.
The wood is not distinguishable in appearance from that of the other poplars or cottonwoods, but it is lighter than most of them, weighing 22.65 pounds per cubic foot, has a breaking strength which places it among the weakest woods, but in stiffness making a much better showing.
The pores are small, numerous, and are distributed equally through all parts of the wood.
Balm of Gilead bears seeds abundantly and scatters them widely. It must do its planting quickly in the short summers of the cold North. It sticks close to alluvial flats, banks of rivers, borders of lakes and swamps, and gravelly soils. It grows to a diameter of fifteen inches in about forty-five years.
Though balm of Gilead is not one of the most important timber trees of this country, its place is by no means obscure. No separate tally is kept of it among woods cut for pulp, but it goes with aspen and other similar species as "poplar." A little better account is kept of the amount pa.s.sing through wood-using factories. The annual quant.i.ty so reported in Illinois is 2,775,000 feet, and it is made into boxes and crates. The lumber is shipped from the North, since it does not grow as far south as Illinois. The situation is different in Michigan, for balm of Gilead grows there. The amount going yearly into factories in that state is reported at 4,912,000 feet. It is made into many commodities, but boxes and crates take most of it. The wood is reduced to veneer and converted into berry buckets, grape baskets, fruit and egg crates, and other small shipping containers. It is made into excelsior and woodwool which are used as packing material. Druggist"s barrels are manufactured from this wood. These are small, two-piece vessels, bored hollow, with a closely fitting lid, and varying in size from a couple of inches high, to nearly a foot. They contain powders, perfumes, pills, and other commodities in small bulk. The wood is worked into pails, tubs, and kegs. Furniture makers put balm of Gilead to use in several ways. It is cut thin for shelving; it is made into panels, and is employed as cores over which to lay veneers of more expensive materials. Woodenware factories generally keep it in stock in the northern states.
The supply is ample at present to meet all demands. Cutters of pulpwood probably take more than sawmills, and are satisfied with smaller timber.
Trees are often planted for ornament, but few if any have yet been propagated for forestry purposes.
HAIRY BALM OF GILEAD (_Populus balsamifera candicans_) is not a species but a variety, and it is so different from balm of Gilead that it is ent.i.tled to a place of its own. Ordinarily it pa.s.ses under the common names applied to balm of Gilead. It is a cultivated tree in eastern Canada and northeastern United States, where it has escaped from cultivation and is running wild. Both Sargent and Sudworth say that nothing is definitely known of the tree"s native range; while it has been claimed by others that it once grew wild in Michigan but was destroyed by lumbermen. Probably most planted balm of Gileads are of this variety, as they are very ornamental. It is a large tree with branches less upright and crowns more open than in the wild species. The leaves are wide, heart-shaped, and are usually silvery white beneath with minute hairs on the margins, on the veins, and leaf stems. It is not improbable that this variety could be more profitably planted for forestry purposes than the species which grows wild; but there is no present indication that foresters favorably consider either of them.
LARGETOOTH ASPEN (_Populus grandidentata_) is named on account of the shape of the leaves. It is sometimes called aspen, popple, white poplar, and large poplar. The wood weighs 28.87 pounds per cubic foot, and is the heaviest of the poplar group except Fremont cottonwood of the arid southwestern regions. The wood is white, attractive, but not strong. It was formerly manufactured into chip hats and shoe heels in New England, and is now used for baskets, crates, boxes, buckets, refrigerators, excelsior, and pulp. Northern factories usually give it the general name "poplar," and for that reason its importance in the lumber trade is underestimated. Trees may reach a height of seventy feet with a diameter of two; but a height of forty or fifty is more usual. The species" range extends from Nova Scotia to Minnesota, southward to Delaware and Illinois, and along the Appalachian mountains to North Carolina and Tennessee.
GUMBO LIMBO (_Bursera simaruba_) is a south Florida species and is known also as West Indian birch. It is in a family by itself with no near relative. It is not a birch. The wood is spongy and very light, weighing less than nineteen pounds per cubic foot. It decays with remarkable rapidity. Branches thrust in the ground take root and grow. An aromatic resin, exuding from wounds in the bark, is manufactured into varnish.
The leaves are subst.i.tuted for tea, and gout remedies are made from the resin. Large trees are fifty feet high and two feet or more in diameter.
Another Florida tree, not in the same family as this, is also called gumbo limbo (_Simarouba glauca_), paradise tree, and bitter wood.
Ailanthus (_Ailanthus glandulosa_) is in the same family as paradise tree, but is not native in this country, though extensively planted here.
ANGELICA TREE (_Aralia spinosa_). This is a small tree, which usually develops little or no heartwood. The springwood, or the inner and porous part of the ring, is broad and yellow, the summerwood, or exterior part of the ring, is narrow and dark. The wood"s figure, due to the marked contrast between the outer and inner portions of the rings, is strong.
When finished it shows a rich yellow, but somewhat lighter than dwarf sumach which it resembles. It is made into small shop articles, like b.u.t.ton boxes, photograph frames, pen racks, stools, and arms for rocking chairs. Its range extends from Pennsylvania to Texas. It is sometimes known as Hercules" club.
ASPEN (_Populus tremuloides_) is widely known but not everywhere by the same name. It is called quaking asp, mountain asp, aspen leaf, white poplar, popple, poplar, and trembling poplar. The peculiarity of the tree which is apt to attract attention, and which gives it most of the names it carries, is the leaf"s habit of being nearly always in motion. The day is remarkably still if aspen foliage is not stirring. This is due to the long, flat leaf stem, which is so limber that it offers little resistance to air currents. The difference in color between the upper and lower sides of the leaves affords sufficient contrast to attract notice, and for that reason a person will observe the motion of aspen leaves when he might fail to see a similar movement among the leaves of other species where the contrast of colors is not so marked. Aspen is credited with being the most widely distributed tree of North America. It grows from Tennessee to the Arctic ocean, from Mexico to northern Alaska, from Labrador to Bering strait. It is found at sea level, and at 10,000 feet elevation among the mountains of California. Its very small seeds grow in enormous numbers. Winds carry them miles, and scatter them by millions. They spring up quickly when they fall on mineral soil. This places it in the cla.s.s with "fire trees"--those which take possession of burned tracts. Paper birch is in this cla.s.s.
Aspen has replaced pines over large burned areas of the Rocky Mountains. It grows quickly but is weak if it has to contend with other trees. If crowded it speedily gives up the fight and dies. The wood is not strong, but is useful for several purposes. Next to spruce and hemlock, it is the most important pulpwood in this country, and it is coming into considerable use as lumber. The whiteness of the wood--it looks much like holly--makes it a favorite for small boxes and vessels for shipping and containing foods. It is made into jelly buckets, lard pails, fish kits, spice kegs, sugar buckets and a long line of similar articles. It turns well, and is made into wooden dishes. Michigan alone uses two and a half million feet of it a year; and it is in demand along the whole northern tier of states from Maine to Washington, but because it is not separately listed in lumber output, it is difficult to say how much is used.
Trees are usually small, though trunks three feet in diameter are not unknown. It grows rapidly, and may be expected to fill an important place in this country"s future timber supply. There will be no occasion to plant it by artificial means, for nature will attend to the planting.
[Ill.u.s.tration]
BLACK COTTONWOOD
[Ill.u.s.tration: BLACK COTTONWOOD]
BLACK COTTONWOOD
(_Populus Trichocarpa_)
This member of the cottonwood group is a strong tree that holds its ground in various lat.i.tudes and at many elevations, ranging from sea level up to eight or nine thousand feet, and in lat.i.tude from Alaska to southern California, a distance of nearly three thousand miles. Its east and west extension is more restricted and seldom exceeds four hundred miles. Its habitat covers an area of half a million square miles, and in that s.p.a.ce it finds conditions which vary so greatly that the tree which can meet them must possess remarkable powers of adaptation.
Beginning in Alaska and the interior of Yukon territory, it has an arctic climate. It there not only grows on the coast, but it strikes the interior. It appears on the headwaters of several streams which flow into the Mackenzie or Hudson bay. It pa.s.ses south through British Columbia and enters the United States west of the Rocky Mountains. It has been reported as far east as Idaho and Montana, but further information is needed before its limits in that direction can be definitely fixed.
When it enters California it prefers the elevated valleys and canyons of the Sierra Nevadas, though it occurs sparingly among the coast ranges.
It is generally found in the Sierras at elevations of from 3,000 to 6,000 feet, though it occurs between 8,000 and 9,000. Among the San Jacinto mountains of southern California it grows at an alt.i.tude of 6,000 feet.
When it occurs at low levels it is usually found on river bottoms and sand bars, in sandy and humous soils, and there the largest trees are found. At higher elevations it is more apt to occur in canyon bottoms and gulches, in moist, sandy or gravelly soil, and in such situations the black cottonwood is smaller. The best growth occurs where the climate is humid and the precipitation is great. Beyond the reach of sea fogs, where the tree depends on soil moisture chiefly, it is smaller.
It is an intolerant tree. It must have light. When it is crowded a tall, slender trunk is developed and the small crown is lifted clear above its compet.i.tors into the full light. If it cannot succeed in gaining that position its growth is stunted or the tree meets an early death.
The black cottonwood is the greatest of the cottonwoods. This country produces no other to match it, and, as far as known, the whole world has none. The Pacific coast is remarkable for the giant trees it produces, but most of them are softwoods--the redwoods, the bigtree, the sugar pine, Douglas fir, western larch, n.o.ble fir, Sitka spruce and western red cedar. This cottonwood is the largest of the Pacific coast hardwoods. In trunk diameter it is excelled by the weeping oak in the interior valleys of California, but when both height and diameter are considered, the black cottonwood is in the West what yellow poplar is in the East, the largest of the hardwoods.
Sargent says this tree reaches a height of two hundred feet and a diameter of eight, but Sudworth is more conservative and places the trunk limit at six feet. The average size is much below the figures given, but abundance of logs exceeding three feet in diameter reach the sawmills of Washington and Oregon.
Old trees range from 150 to 200 years in age, but trees under 100 years old are large enough for saw timber. Records of the ages of the largest trunks have not been reported.
Black cottonwood is a prolific seeder, but the seeds do not long retain their vitality. If they find lodgment in damp situations, where other conditions are favorable, the rate of germination is high. Seedlings are often very numerous on wet bars.
The excellent quality of the wood and its suitability for many purposes bring it much demand on the Pacific coast. In the state of Washington more than 30,000,000 feet were used by wood-using industries in 1910.
Smaller quant.i.ties were reported in Oregon and California.
In strength the wood is approximately the same as common cottonwood, but in stiffness it much exceeds the eastern species. Its elasticity rates high, and compares favorably with some of the valuable eastern hardwoods. In weight it is slightly under common cottonwood. Trees are of fine form, nearly always straight, and are generally free from limbs to a considerable height.
The wood is grayish-white, soft, tough, odorless, tasteless, long-fibered, nails well, is easily glued, and cuts into excellent rotary veneer with comparatively small expenditure of power. It does not split easily after it has undergone seasoning, and this property commends it to box makers. It is little disposed to shrink and swell in atmospheric changes. The absence of odor and taste gives it much of its value for box making, because foods are not contaminated by contact with it.
It is manufactured into veneer berry baskets and is one of the most suitable woods on the Pacific coast for that purpose. Candy barrel makers use it in preference to most others, and a long line of woodenware articles draw much of their material from this source. Many thousands of cords are cut yearly for the pulp mills, where material for paper is produced. Black cottonwood and white fir are the princ.i.p.al woods used for pulp on the Pacific coast.
Not only is it used for rotary-cut veneer, but it is made into cores or backing on which veneers of costly woods are glued in the manufacture of furniture, interior finish and fixtures for banks, stores and offices.
It serves in the same way in casket making, and is demanded in millions of feet.
It is employed in amounts larger than any other wood by excelsior mills in the northern Pacific coast region. It is the only wood demanded by that industry in Washington and 6,400,000 feet were cut into that product in 1910.
Slack coopers find it as valuable in their business in the far West as the common cottonwood is in the East, and hundreds of thousands of staves are made yearly. It is in demand for the manufacture of flour barrels and those intended for other food products.
Trunk makers use it in three-ply veneers for the bodies, trays, boxes and compartments of trunks and for suit cases. Though soft and light, it is very tough, and sheets of veneer with the grains placed transversely resist strains much better than solid wood of the same thickness.
Vehicle makers employ black cottonwood for the tops and shelves of business wagons. Another of its uses is as bottoms of drawers for bureaus, wardrobes, and chiffoniers, and as part.i.tions in desk compartments. A full line of kitchen and pantry furniture is made wholly or in part of this wood in the regions where it is cheap and abundant.
The cottonwoods belong to a very ancient race of broadleaf trees, and like several others, they seem to have had their origin, or at least a very early home, in the far North, where intense cold now excludes almost every form of vegetable growth except the lowest orders. The Cretaceous age saw cottonwoods growing in Greenland. The cotton which then, as now, carried the seeds and planted them fell on more hospitable sh.o.r.es then than can now be found in the far frozen North. The genus was not confined to the arctic and subarctic regions, however, for there were cottonwoods at that time, or later, in more southern lat.i.tudes.
There were many species in the central portion of this country, and also in Europe, long before the ice age destroyed all the forests north of the Ohio and the Missouri rivers. Some of the old species long ago ceased to exist, but others appear to have come down to the present time without great change.
The cottonwood shows wonderful vitality, which is doubtless a survival of the characteristic which enabled it to come down from former geologic epochs to the present time. A damaged and mutilated tree will recover. A broken limb, thrust in the ground, will grow.
BLACK POPLAR (_Populus nigra_) is quite distinct from black cottonwood, though both belong to the same family. The latter is a Pacific coast species, while the former belongs in Europe, although it may have been introduced into that country from Persia or some other eastern region. It is common in the United States, on account of having escaped from cultivation. The best known variety of this tree is the Lombardy poplar (_Populus nigra italica_). It is easily recognized by the characteristic att.i.tude of the branches which grow upward close against the trunk. The crowns of the trees are very long and slender, sometimes not ten feet across though fifty feet high. Their slimness gives the trees the appearance of being much taller than they really are. They were formerly popular for planting along lanes and in door yards. Their slender and pointed spires cut the horizon with a peculiar effect. Planting is less common now than formerly, because people have come to know the trees better. They are probably the most limby of all the members of the cottonwood group. The long trunks are ma.s.ses of knots when the limbs have been trimmed away, and any desire to make lumber of the trees is apt to be discouraged, though not infrequently logs go to local sawmills, and farmers haul the boards home to put them to some use about the place. In Michigan and Ohio, box makers use the lumber for the rougher and cheaper articles which they turn out.
The most discouraging thing about Lombardy poplar is the tendency of the trees to send up sprouts. The living trees do it, and the stumps are worse. The sprouts are not confined to the ground immediately round the base of the tree, but spring up many feet or many yards distant, until they produce a veritable jungle. Years are often required to complete their extermination by grubbing and cutting.