PART III

THE WATER-LOVING TREES

The Poplars--The Willows--The Hornbeams--The Birches--The Alders--The Sycamores, or Buttonwoods--The Gum Trees--The Osage Orange

THE POPLARS

The poplars are plebeian trees, but they have a place to fill and they fill it with credit. They are the hardy, rude pioneers that go before and prepare the way for nobler trees. Let a fire sweep a path through the forest, and the poplar is likely to be the first tree to fill the breach. The trees produce abundant seed, very much like that of willows, and the wind sows it far and wide. The young trees love the sun, and serve as nurse trees to more valuable hardwoods and conifers, that must have shade until they become established. By the time the more valuable species are able to take care of themselves, the poplars have come to maturity and disappeared, for they are quick-growing, short-lived trees. The wind plays havoc with their brittle branches. Seldom has a good-sized poplar tree any claim to beauty.

Tenacity of life, if not of fibre, belongs to the poplar tribe. Twigs strike root and the roots send up suckers from underground: cutting off these suckers only encourages them to fresh activity. The only way to get rid of the young growth that springs up about an old tree is to use the grubbing-hoe thoroughly and patiently.

Poplar blossoms, borne in catkins, show the close relationship between this genus and the willows. The leaves, however, are always broad and leathery, and set on long stems. Twenty-five species are known, twelve of which are American.

=The White Poplar=

_Populus alba_, Linn.

The white poplar is sometimes called the silver-leaved poplar because its dark, glossy leaves are lined with cottony nap. This sprightly contrast of light and shade in the foliage is most unusual, and very attractive in early spring; but the leaf-linings collect soot and dust, and this they carry to the end of the season--a fact which should not be forgotten by those considering the advisability of planting this tree in a city where much soft coal is burned.

The white bark of this European poplar reminds us of the birch family, though it has no silky fringe shedding from the surface. The leaves often imitate the maple in the divisions of their margins, justifying the name "maple-leaved poplar."

As a dooryard tree this species has a wider popularity than it deserves. The wind breaks the brittle branches, and when these accidents threaten its life, the tree sends up suckers which form a grove about the parent trunk, and defy all efforts to eradicate them, until the grubbing-hoe and axe have been resorted to.

=The Black Poplar=

_P. nigra_, Linn.

The Lombardy poplar, a variety of the black poplar of Europe, is a familiar tree figure along roadsides, and often marks boundary lines between farms. Each tree is an exclamation point, its branches short and numerous, rising toward the zenith. The roundish leaves that twinkle on these aspiring branches make the tree pretty and interesting when young--just the thing to accent a group of round-headed trees in a park. But not many years are attained before the top becomes choked with the multitude of its branches. The tree cannot shed this dead wood and the beauty of its youth is departed. The trunk grows coarse, warty, and buttressed at the base. Suckers are thrown up from the roots. There is little left to challenge admiration. Since the tree gives practically no shade, we must believe that the first planters were attracted by its odd shape and its readiness to grow, rather than by any belief in its fitness for avenue and highway planting.

=The Cottonwood=

_P. deltoidea_, Marsh.

The cottonwood justifies its existence, if ever a tree did. On our Western plains, where the watercourses are sluggish and few and often run dry in midsummer, few trees grow; and the settler and traveler is grateful for the cottonwoods. The pioneer on the Western prairie planted it for shade and for wind-breaks about his first home. Many of these trees attain great age and in protected situations are magnificent though unsymmetrical trees, shaking out each spring a new head of bright green, glossy foliage, each leaf responsive to the lightest breeze.

"Necklace-bearing poplar," it has been called, from the fact that children find pleasure in stringing for beads the green, half-grown pods containing the minute seeds. They also delight in gathering the long, red caterpillar-like catkins of the staminate flowers, the pollen bearers, from the sterile trees. A fertile tree is sometimes counted a nuisance in a dooryard because its pods set free a great mass of cotton that collects in window screens, to the annoyance of housewives. But this seed time is soon over.

Just these merits of quick growth, prettiness, and tenacity of life, belong to the Carolina Poplar, a variety of native cottonwood that lines the streets of the typical suburban tract opened near any American city. The leaves are large and shine with a varnish which protects them from dust and smoke. But the wind breaks the branches, destroys the symmetry of the tree's head, and in a few years the suburban community takes on a cheap and ugly look. The wise promoter will alternate slow-growing maples and elms with the poplars so that these permanent trees will be ready to take their places in a few years.

=The Aspen=

_P. tremuloides_, Michx.

The trembling aspen, or quaking asp, is the prettiest tree of all the poplar tribe. Its bark is gray and smooth, often greenish and nearly white. An aspen copse is one of the loveliest things in the spring landscape. In March the bare, angular limbs show green under their bark, one of the first prophecies of spring; then the buds cast their brown scales and fuzzy gray catkins are revealed. There are few shades of olive and rose, few textures of silk and velvet that are not duplicated as the catkins lengthen and dance like chenille fringe from every twig. With the flowers, the new leaves open; each blade limp, silky, as it unrolls, more like the finest white flannel than anything else. (_See illustrations, pages 86-87._) Soon the leaves shed all of this hairy, protective coat, passing through various tones of pink and silver on their way to their lustrous, bright green maturity. Their stems are flattened in a plane at right angles with the blade. Being long and pliant besides, they catch the breeze on blade or stem, and so the foliage is never still on the quietest of summer days. "Popple" leaves twinkle and dance and catch the sunlight like ripples on the surface of a stream, while the foliage of oaks and other trees near by may be practically motionless.

=The Balsam Poplar=

_P. balsamifera_, Linn.

The balsam poplar is the balm of Gilead of the early settlers, the Tacamahac of the Northern Indians. They squeezed the fragrant wax from the winter buds and used it to seal up the seams in their birch-bark canoes. The bees taught the Indian the uses of this glutinous secretion, which the tree used to seal the bud-scales and thus keep out water. When growth starts with the stirring of the sap, this wax softens; then the bees collect and store it against a day of need. Whether their homes be hollow trees or patent hives, weather-cracks are carefully sealed up with this waterproof gum, which the bee-keeper knows as "_propolis_."

Forests of balm of Gilead cover much of the vast British possessions north of the United States, and reach to the ultimate islands of the Aleutian group. They dip down into the states as far as Nebraska and Nevada. In cultivation, the species has proved itself a tree of excellent habit, easily propagated and transplanted, and of rapid growth. It has all the good points of the Carolina poplar and lacks its besetting sin of becoming so soon an unsightly cripple.

=Narrow-leaved Cottonwood=

_P. angustifolia_, James.

=Lance-leaved Cottonwood=

_P. acuminata_, Rydb.

=Mexican Cottonwood=

_P. Mexicana_, Wesm.

These three cottonwoods line the banks of mountain streams at high elevations in the great system of mountain chains that stretch from British Columbia southward. The dancing foliage, bright green in summer, golden in autumn, lends a charming color note to the dun stretches of arid plain and the sombre green of pine forests. These trees furnish the settler fuel, shade, and wind-breaks while he is converting his "homestead" into a home.

=Black Cottonwood=

_P. trichocarpa_, Hook.

Farther west, covering the mountain slopes from Alaska to Mexico, and liking even better the moist, rich lowlands, is the black cottonwood, the giant of the genus, reaching two hundred feet in height, and seven to eight feet in trunk diameter. Tall and stately, it lifts its broad rounded crown upon heavy upright limbs. In the Yosemite the dark, rich green of these poplar groves along the Merced River makes a rich, velvet margin, glorious when it turns to gold in autumn.

=Swamp Cottonwood=

_P. heterophylla_, Linn.

The swamp cottonwood of the South has leaves of variable but distinctly poplar form, always large, broadly ovate, with slim round petioles. The white down of the unfolding leaves often persists into midsummer. On account of the fluttering leaves the trees were called, by the early Acadians, "_Langues de femmes_" a mild calumny traceable to the herbalist, Gerarde, who compares them to "women's tongues, which seldom cease wagging."

The wood of poplars, soft, weak, and of slight value for fuel or lumber, has within two decades come into a position of great economic importance. Wood pulp is made of it, and out of wood pulp a thousand articles, from toys to wheels of locomotives, are made. A state forester declared: "If I could replace the maples in the state forest by poplars to-day, I would do it gladly. It would be worth thousands of dollars to the state."

THE WILLOWS

Along the watercourses the willow family finds its most congenial habitat. It is a very large family, numbering more than one hundred and seventy species, which are, however, mostly shrubs rather than trees. America has seventy species of willows, and new forms are constantly being discovered, which are the results of the crossing of closely related species. These "natural hybrids" have greatly confused the botany of the willow family.

Not more than half a dozen American willows ever attain the height of good-sized trees, and many of these are more commonly found in the tangled shrubbery of river banks, or covering long semi-arid strips of ground far to the north, or on mountain sides where their growth is stunted. Little trees, six inches high, bearing the characteristic catkins and narrow leaves of the willow, are found on the arctic tundras.

The wood of willows is pale in color, soft in texture, and of very little use as lumber or fuel, except in localities where trees are scarce. The Indian depended upon the inner bark of the withy willow for material for his fish nets and lines, and farmers in the pioneer days took the tough, supple stems, when spring made the sap run freely, for the binding together of the rails of their fences. Knotted tight and seasoned, these twigs hardened and lasted for years.

In Europe the white willow has long been used for the making of wooden shoes, artificial limbs, and carriage bodies. Its wood makes the finest charcoal for gunpowder. Willow wares, such as baskets and wicker furniture, are as old as civilization, and that in its primitive stages. It is a common sight in Europe to see groves of trees from which the long twigs have been taken yearly for these uses. The stumps are called "pollards" and the trees "pollarded willows" whose discouraging task has been to grow a yearly crop of withes for the basket-makers; yet each spring finds them bristling with the new growth.

The hosts of Cæsar invading England in the First Century found the Britons defending themselves behind willow-woven shields, and living in huts of wattled willows, smeared with mud. From that time to the present the uses of these long shoots have multiplied.

The roots of willows are fibrous and tough as the shoots. For this reason they serve a useful purpose in binding the banks of streams, especially where these are liable to flood. Nature seems to have designed these trees for just this purpose, for a twig lying upon the ground strikes root at every joint if the soil it falls on is sufficiently moist. The wind breaks off twigs and the water carries them down stream where they lodge on banks and sand bars, and these are soon covered with billows of green.

Willows start growth early in spring, putting out their catkins, the two sexes on different trees, before the opening of the leaves. Before the foliage is full grown, the light seeds, each a minute speck, floats away in a wisp of silky down. Its vitality lasts but a day, so it must fall on wet ground at once in order to grow. But the willow family is quite independent of its seeds in the matter of propagation. Chop the roots and twigs into bits and each will grow. Chop a young willow tree into sticks and fence posts and each one, if it is stuck green into the ground, covers itself with a head of leafy twigs before the season is over.

=Weeping Willow=

_Salix Babylonica_

The weeping willow, much planted in cemeteries and parks, came originally from Asia and is remarkable for its narrow leaves that seem fairly to drip from the pendulous twigs. (_See illustration, page 55._) The foliage has a wonderful lightness and cheerfulness of expression, despite its weeping habit.

=The Pussy Willow=

_S. discolor_, Muehl.

The pussy willow is the familiar bog willow, whose gray, silky catkins appear in earliest spring. A walk in the woods in late February often brings us the charming surprise of a meeting with this little tree, just when its gray pussies are pushing out from their brown scales. We cut the twigs and bring them home and watch the wonderful color changes that mark the full development of the flowers. Turning them in the light, one sees under the sheen of silky hairs the varied and evanescent hues that glow in a Hungarian opal. In midsummer a pussy willow tree is lost among the shrubby growth in any woods. It is only because it leads the procession of the spring flowers that every one knows and loves it. (_See illustrations, pages 86-87._)

THE HORNBEAMS

Two genera of little trees in the same family with the birches are frequently met in the woods, often modestly hiding under the larger trees. One is the solitary representative of its genus: the other has a sister species.

The hornbeams grow very slowly and their wood is close-grained, heavy, and hard. In flexibility, strength, and ability to stand strain, it rivals steel. Before metals so generally became competitors of woods in construction work, hornbeam was the only wood for rake teeth, levers, mallets, and especially for the beams of ox yokes. It outwore the stoutest oak, the toughest elm. Springiness adapted it for fork handles and the like. Bowls and dishes of hornbeam lasted forever, and would never leak nor crack. "Ironwood" is the name used wherever the wood was worked.

=American Hornbeam=

_Carpinus Carolinianum_, Walt.

The American hornbeam has bluish gray bark, very fine in texture, from which the name "blue beech," is common in some localities. "Water beech" points out the tree's preference for rich swamp land.

The trunk and limbs are strangely swollen, sometimes like a fluted column, oftener irregularly, the swelling under the bark suggesting the muscular development of a gymnast's arm.

In favorable places the hornbeams grow into regular oval heads, their branches dividing into a multitude of wiry, supple twigs. Crowded under oaks and other forest growth, they crouch and writhe; and their heads flatten into tangled masses of foliage.

The delicate leaves, strong-ribbed, oval, pointed, turn to red and orange in autumn. (_See illustration, page 87._) The paired nutlets are provided with a parachute each, so that the wind can sow them broadcast. This wing is leafy in texture, shaped like a maple leaf, and curved into the shape of a boat. After they have broken apart, the nutlets hang by threads, tough as hornbeam fibres always are. At last, away they sail, to start new trees if they fall in moist soil.

The European hornbeam was a favorite tree for making the "pleached alleys," of which old-world garden-lovers were proud. A row of trees on each side of a promenade were pruned and trained to cover an arching framework, and to interlace their supple branches so that at length no other framework was needed, and one walked through a tunnel of green so closely interlaced as to make walls and roof that shut out light and wind and rain! Hedges, fences, and many fancies of the gardener were worked out with this hornbeam, so willingly did it lend itself to cutting and moulding into curious forms.

=Hop Hornbeam=

_Ostrya Virginiana_, Willd.

The hop hornbeam has habits like the other ironwood and an equal reputation for the hardness of its wood. The tree, however, wears scaly, shaggy brown bark, suggesting in its manner of scaling off the shagbark hickory. Its nutlets are packed separate in loose papery bags, and together form a loose, cone-like cluster, like the fruit of a hop vine. The wind scatters these buoyant little bags, that travel far.

This tree often twists in growing, and the trunk shows spiral furrows. "Hard-tack," "beetle-wood," "lever-wood"--all take us back to the pioneer who put this wood to such good uses, and who was glad to have these little trees growing in his wood-lot. In hickories, even, he had not the equal of them for strength and hardness.

=Knowlton's Ironwood=

_O. Knowltoni_, Cov.

Knowlton's ironwood is found nowhere but in a thick grove on the southern slope of the canyon of the Colorado in Arizona, about seventy miles north of Flagstaff. Here these trees are numerous, crouching under oaks, their twisted branches ending in drooping twigs, bearing the characteristic pale green hops in autumn, small oval leaves, and the catkin flowers in spring. Such a restricted distribution for a distinct species of trees is unmatched in the annals of botany.

THE BIRCHES

Grace and gentility of appearance are attributes of this most interesting, attractive, and valuable family of trees. _Shabby_ gentility, one may insist, thinking of the untidy, frayed-out edges that adorn the silky outer bark of almost every birch tree in the woods. (_See illustration, page 102._) Not one of them, however, but lends a note of cheerfulness to the landscape. There is beauty and daintiness in leaf, flower, and winged seed, and despite the inferiority of most birch wood, the history of the family is a long story of usefulness to the human race.

About thirty species of birches grow in the Northern Hemisphere, ten of them are North American. The white birch of Europe extends across the northern half of Asia, and is cultivated in delicate cut-leaved and weeping forms, as a lawn and park tree in this country.

=The Canoe Birch=

_Betula papyrifera_, Marsh.

The canoe birch or paper birch is the noblest member of the family. (_See cover of book._) Ernest Thompson Seton calls it "The White Queen of the Woods--the source of food, drink, transport, and lodging to those who dwell in the forest--the most bountiful provider of all the trees." Then he enumerates the sweet syrup yielded by its sap; the meal made by drying and grinding the inner bark; the buds and catkins upon which the partridge feeds; and the outer bark, which is its best gift to primitive man.

"The broad sheets of this vegetable rawhide, ripped off when the weather is warm, and especially when the sap is moving, are tough, light, strong, pliant, absolutely waterproof, almost imperishable in the weather; free from insects, assailable only by fire. It roofs the settler's shack and the forest Indian's wigwam. It supplies cups, pails, pots, pans, spoons, boxes; under its protecting power the matches are safe and dry; split very thin, as is easily done, it is the writing paper of the woods, flat, light, smooth, waterproof, tinted, and scented; but the crowning glory of the birch is this--it furnishes the indispensable substance for the bark canoe, whose making is the highest industrial exploit of the Indian life."

From the Atlantic to the Pacific, and from our northern tier of states to the arctic seas, woodsmen, red and white, have found this white-barked tree ready to their hand, their sure defense against death by cold and by starvation. The weather is never so wet but that shreds of birch bark burn merrily to start a campfire, and the timber of the trunk burns readily green or dry.

=The White Birch=

_B. populifolia_, Marsh.

The white birch is a small, short-lived tree that grows in swampy ground, its bark chalky white or grayish, with triangular rough patches of black, where branches are or have been. (The canoe birch has a clean bole, chalky white, with none of these ugly black patches.)

A vagabond tree it is, with thin pointed leaves and long pencil-like catkins and seed cones. The chief contributions of the poplar-leaved birch to the well-being of men are that it clothes with beauty the most uninviting situations, and that it comes again, after fire or other general slaughter, promptly and abundantly, from stump and scattered seed.

=The Yellow Birch=

_B. lutea_, Michx.

The yellow birch shows gleams of yellow under every rent in its gray, silky, frayed-out surface. Here is a timber tree of considerable size and value: its hard wood furnishes the frames of northern sledges; the knots and burs make good mallets; the curiously knotted roots show a curly grain, valuable to the cabinet-maker. From New England to Minnesota, and south along the Appalachian range, this tree is found, always telling its name by the color of its shaggy bark.

=The Red Birch=

_B. nigra_, Linn.

Red birch or river birch wears its name in its chocolate-hued or terra-cotta bark, whose scaly surface flaunts a series of tattered fringes to the very twig ends. Tall and graceful fountains of living green, these birches lean over stream borders from Minnesota and New York to the Gulf of Mexico, and reach westward to the foothills of the Rockies. Close-grained and strong, the pale brown wood is used for furniture, shoe lasts, and a multitude of woodenwares. In the bayous of the lower Mississippi, where its roots and the base of the trunk are inundated for half the year, the tree reaches its greatest size. The cones stand erect and shed their heart-shaped, winged seeds in June--an exception to the autumn-fruiting of all other birches.

=The Cherry Birch=

_B. lenta_, Linn.

The cherry birch has dark, irregularly checked bark like the wild cherry, but the oval, pointed leaf, the catkin flowers, and the cone fruits of its family. Birch beer is made of its aromatic sap and wintergreen oil is extracted from the leaves. Indians shred the inner bark and dry it in the spring when it is rich in starch and sugar. These shreds, like vermicelli, are boiled with fish and form a nourishing dish. The wood is heavy, hard, and close-grained, valuable for the manufacture of furniture and implements, especially wheel hubs, and for fuel. It is one of the handsomest, most symmetrical, and most luxuriant of all our birch trees, and a worthy addition to any park.

THE ALDERS

Closely related to the hornbeams and birches is a genus of small water-loving trees that grow rapidly and serve definite, special uses in the Old and New World. The genus _alnus_ includes twenty species, nine of which grow in North America; six of these reach the height of trees.

=The Black Alder=

_Alnus glutinosa_, Gaertn.

Of the alders, the black alders of Europe is the largest and most important timber tree. Its range includes western Asia and northern Africa. It was introduced successfully into our Northeastern states in colonial times and has become naturalized in many localities. These trees sometimes reach seventy feet in height and a trunk diameter of three feet. Their dark green foliage, glutinous when the leaves unfold in the spring, ranks these giant alders among the beautiful and picturesque trees.

The lumberman esteems alder wood only for special purposes. It grows in water and its wood resists decay better than any other kind when saturated through indefinite periods. In the old days it was the wood for the boat-builder. The piles of the Rialto in Venice and along the canals of Amsterdam and other Dutch cities are of black alder. Water pipes and troughs, pumps, barrel staves, kneading troughs, sabots and clogs were made of alder wood. The bark and cones are rich in tannin and a yellow dye used in making ink. Willow and alder make the best charcoal for gunpowder. Warty excrescences on old trees and twisted roots furnished the inlayer with small but beautifully veined and very hard pieces, beautiful in veneer work when polished. In America the black alder is often met in horticultural varieties. The daintiest are the cut-leaved forms, of which _imperialis_, with leaves fingered like a white oak, is a good example.

One of the best uses to which alders are put in Europe is planting in hedges along borders of streams, where their closely interlacing roots hold the banks from crumbling and keep the current clear in midstream. No English landscape is more beautiful than one through which a little river winds, its banks and the boggy spots tributary to it softened by billows of living green. "He who would see the alder in perfection must follow the banks of the Mole and Surrey through the sweet vales of Dorking and Wickleham."

=Seaside Alder=

_A. maritima_, Nutt.

The seaside alder shares with the witch hazel the peculiar distinction of bearing its flowers and ripening its fruit simultaneously in the fall of the year. The alder comes first, hanging out its golden catkins in clusters on the ends of the season's shoots in August and September. Nothing is left of them when the witch hazel scatters its dainty stars along the twigs in October and November. The seaside alder follows stream borders near but not actually on the seacoast, through eastern Delaware and Maryland, but ranges comfortably on drier soil as far west as Oklahoma and is hardy in gardens and parks as far north as Boston, where it blooms profusely and is much admired for both flowers and glossy foliage through the late summer.

=Oregon Alder=

_A. Oregona_, Nutt.

The Oregon or red alder reaches eighty feet in height and its trunk may exceed three feet in diameter. This Western tree exceeds the Old World alder in size. The smooth, pale-gray bark reminds us of the beech and sets this tree apart from the white alder whose bark is brown and deeply furrowed. The flowers and cone fruits are very large. The ovate leaves are cut-toothed and often lobed. This is the alder of the West Coast, largest where it comes down to the sea near the shores of Puget Sound, but climbing the mountains and canyon sides wherever there is water, from Sitka to Santa Barbara. The reddish brown wood is light, easily worked, and beautifully satiny when polished. In Washington and Oregon it is largely used in the manufacture of furniture. The Indian dug-outs are made of the butts of large trees.

THE SYCAMORES, OR BUTTONWOODS

=The Buttonwood=

_Platanus occidentalis_, Linn.

Our eastern buttonwood is a tree to which, in America, we supply the name sycamore. Its European counterpart is the plane tree of the Old World. It is one of the easiest trees to recognize, for its most prominent trait is fairly shouted at us from a distance, whenever one of these trees comes within the range of our vision. The smooth bark that covers the branches is thin, very brittle, and has the habit of flaking off in irregular plates, leaving white patches under these plates that contrast sharply with the dingy olive of the unshed areas. On old trunks the bark is reddish brown and breaks into small, irregular plates; but above, and out among the branches, the tree looks downright untidy, and as though it had been splashed with whitewash by some careless painter. (_See illustrations, pages 102-103._)

White birches grow in copses in low ground, a whole regiment of their white stems slanting upward. But the ghostly sycamore is apt to stand alone along the river-courses, scattered among other water-loving trees. The tree is wayward in its branching habit, its twigs irregular and angular. When the leaves are gone, it is a distressed-looking object, dangling its seed-balls in the wind until the central, bony cob is bare, the seeds having all sailed away on their hairy parachutes.

In the warmer South our buttonwood is a stalwart, large-limbed tree of colossal trunk, that shelters oaks and maples under its protecting arms. And there are some large specimens on Long Island.

The buttonwood leaf in a general way resembles a maple's, being as broad as long, with three main lobes at the top. The leaf stem forms a tent over the bud formed in summer and containing the leafy shoot of the next year. The leaf scar, therefore, is a circle and the leaf base a hollow cone. At first a sheathing stipule, like a little leafy ruffle, grows at the base of each leaf, but this is shed before midsummer.

=Oriental Plane=

_P. Orientalis_, Linn.

The oriental plane is almost as familiar a tree as our native species, for it is planted as a street tree in every city and village, and is a favorite shade and lawn tree besides. The city of Washington has set the example and so has Philadelphia. One third of the street trees of Paris are plane trees.

The chief merits of this tree immigrant are its perfect hardiness, its fine, symmetrical, compact pyramid, its freedom from injury by smoke and dust, and its rapid growth in the poor soil of the parkings of city and village. In leaf and fruit and bark-shedding habit, it is easily recognized as a sycamore, though in this species more than one ball dangles from each stem.

The exactions of city life limit the number of tree species that will do well. Our native sycamore patiently endures the foul breath of factory chimneys, and helps, in the smallest, downtown city parks, to make green oases in burning deserts of brick and stone pavements. But it is subject to the ravages of insect and fungous enemies to a greater extent than the oriental species.

THE GUM TREES

Southern people talk more about "gum trees" than people in the North. Two of our three native species of Nyssa belong solely to southern swamps, and the third, which comes north to Canada, is oftener called by other names. All these trees are picturesque, with twiggy, contorted branches; tough, cross-grained wood; alternate, simple, leathery, but deciduous leaves, beautiful at all seasons; minute flowers and fleshy, berry-like fruits.

=The Sour, or Black, Gum=

_Nyssa sylvatica_, Marsh.

The sour or black gum of the South has a wide range, being hardy to southern Ontario and Maine. To the New Englander this is the "pepperidge"; the Indians called it "tupelo"; but the woodsman, North and South, calls it the gum tree, as a rule. "Black gum" refers to its dark gray, rough bark, which is broken into many-sided plates. By this, it is easily distinguished from the "red gum" or liquid amber, which grows in the same situations, but is not related to it. "Sour gum" refers to the acid, blue-black berries, one to three in a cluster, ripe in October.

We shall know this tree by its tall, slender trunk, clothed with short, ridged, full-twigged, horizontal branches. With no claim to symmetry, the black gum is a striking and picturesque figure in winter. It is beautiful in summer, covered with the dark polished leaves, two to four inches long. In autumn patches of red appear as the leaves begin to drop. This is the tupelo's signal that winter is coming. Soon the tree is a pillar of fire against yellowing ashes and hickories. The reds of the swamp maple and scarlet oak are brighter, but no tree has a richer color than this one. A spray brought in to decorate the mantelpiece lasts till Christmas holly displaces it. The leaves, being leathery, do not curl and dry, as do thin maple leaves, in the warm air of the house.

=The Cotton Gum=

_N. aquatica_, Marsh.

The cotton gum is draped in cottony white down as the new shoots start and the leaves unfold in spring. In midsummer this down persists in the leaf-linings, lightening the dark green of the tree-tops. The dark blue fruits of this species have no culinary value. The wood is used for crating material. The tree reaches its maximum height--one hundred feet--in the cypress swamps of Louisiana and Texas, its abundant, corky roots adapting it to its habitat.

=The Sweet Gum=

_Liquidamber styraciflua_, Linn.

The sweet gum is a tall tree with a straight trunk, four to five feet in diameter, with slender branches covered with corky bark thrown out in wing-like ridges. At first the head is regular and pyramidal, but in old age it becomes irregularly oblong and comparatively narrow. The bark is reddish brown, deeply furrowed between rough scaly plates, marked by hard, warty excrescences.

The leaves are lobed like a maple's, but more regularly, so as to form a five-pointed star. Brilliant green in summer, they become streaked with crimson and yellow. Wherever these gum trees grow, the autumn landscape is painted with the changeful splendor of the most gorgeous sunset. "The tree is not a flame, it is a _conflagration_!" Often along a country road the rail fence is hidden by an undergrowth of young gum trees. Their polished star leaves may pass from green into dull crimsons and then into lilacs and so to brown, or they may flame into scarlets and orange instead. Always, the foliage of the sweet gum falls before it loses its wonderful colors.

The flowers of the sweet gum are knobby little bunches; the swinging balls covered with curving horns contain the winged seeds, small but shaped like the key of the maple. One recognizes the gum tree in winter by these swinging seed-balls, an inch in diameter, like the balls of the buttonwood, except that those are smooth. (_See illustrations, pages 102-103._) The best distinguishing mark of sweet gums in winter are the corky ridges on the branches, and the star-shaped leaves under the trees. Sweet gum sap is resinous and fragrant. Chip through the bark, and an aromatic gum soon accumulates in the wound. The farther South one goes, the more copious is the exudation. In Mexico a Spanish explorer described, in 1651, "large trees that exude a gum like liquid amber." This is the "copalm balm" gathered and shipped each year to Europe from New Orleans and from Mexican ports. The fragrant gum, _storax_ or _styrax_, derived from forests of the oriental sweet gum in Asia Minor, is used as incense in temples of various oriental religions. It blends with frankincense and myrrh in the censers of Greek and Roman Catholic churches. It is used in medicines also, and as a dry gum is the standard glove perfume in France.

Beautiful and interesting in every stage of growth, our native sweet gums are planted largely in the parks of Europe and are earning recognition at home, through the efforts of tree-lovers who would make the most of native species in ornamental planting.

The name, gum tree, is applied to our tupelos, and to the great tribe of Australian eucalyptus trees, now largely planted in the Southwest.

=The Osage Orange=

_Toxylon pomiferum_, Raff.

Related to figs and mulberries, but solitary in the genus _toxylon_, is the osage orange, a handsome round-headed tree, native of eastern North America, whose fleshy roots and milky, bitter, rubbery sap reveal its family connections with the tropical rubber plants. (_See illustration, page 119._) The fruits are great yellow-green globes, four to five inches in diameter, covered on the outside by crowded, one-seeded berries. This compound fruit reveals the tree's relationship to both figs and mulberries.

The aborigines, especially of the Osage tribe, in the middle Mississippi Valley, cherished these trees for their orange-yellow wood, which is hard, heavy, flexible, and strong--the best bow-wood to be found east of the Rocky Mountains. When the settlers came the sharp thorns with which the branches are effectually armed appealed strongly to the busy farmers and the tree was widely planted for hedges. Nurserymen produced them by thousands, from cuttings of root and branch. These trees made rapid growth and seemed most promising as a solution of the fencing problem, but they did not prove hardy in Iowa and neighboring states. Even now remnants of those old winter-killed hedges may be found on farm boundaries, individual trees having been able to survive.

The native osage orange timber is about all gone, for the rich bottom lands where it once grew most abundantly in Oklahoma and Texas have been converted into farm land. However, the growing of osage orange timber for posts is on the increase. Systematically maintained, plantations pay well. The wood is exceptionally durable in soil. Good prices are paid for posts in local markets. Twenty-five posts can be grown to the rod in rows of a plantation; they grow rapidly and send up new shoots from the roots.

The brilliant, leathery leaves and conspicuous green fruits make this native bow-wood a very striking lawn tree. It holds its foliage well into the autumn and turns at length into a mass of gold. It harbors few insects, has handsome bark, and is altogether a distinguished, foreign-looking tree.

Experiments of feeding osage orange leaves to silkworms have been successfully made at different times, but nowhere in America has silk culture succeeded. Since the white mulberry is hardy here and its foliage is the basis of the silk-growing industry in the Old World, it is futile to look for substitutes in the osage orange or any other tree.