sidered by many botanists as a species, and B. a. 4 póntica; B. póntica Lodd. Cat., ed. 1836; B. a. 5 urticifòlia, B. urticifolia Lodd. Cat., has the leaves deeply laciniated, serrated, and hairy. 1549 B. a. 6 dalecárlica L. Supp., 416., is described by the younger Linnæus, as having its leaves almost palmate, with the segments toothed; "cut like those of hemp," according to Bosc. B. a. 7 macrocarpa Willd. has the female catkins twice as long as those of the species. B. a. 8 foliis variegàtis Dumont has the leaves blotched with yellowish,white. Other Varieties. B. populifòlia and B. daùrica, given below as species, are, we think, as much varieties as the preceding sorts; for, though B. populifòlia will come tolerably true from seed, yet it is often produced from seeds of the common birch. B. daùrica appears to be a variety of B. álba, stunted from the climate in which it grows; and the same observation will apply to B. sibírica,.and some others, enumerated in the Catalogue of Messrs. Loddiges for 1836. B. excélsa and B. nigra of some of the London gardens are mere varieties of the common birch, and quite distinct from the species described by botanists under these names, which are natives of America. (See Gard. Mag., vol. xi. p. 502. 689.) There are some other sorts in the collection at Messrs. Loddiges's; such as B. undulata, B. Thouiniana and B. Fischèrü, which appear to us to belong to B. álba; but, the plants being exceedingly small, we are not able to determine this with certainty. B. laciniata being merely a cut-leaved variety of B. populifòlia, we have included it under that head; as we have the sort named B. péndula, in the collection of the Messrs. Loddiges. We prefer, in this case, as in similar ones, giving varieties which have been generally considered species as such, merely indicating our opinion by a letter in parentheses, for the sake of disposing of the synonymes. There are some varieties of a trifling nature given by Linnæus in his Flora Suecica: such as one with a rounder leaf than the species, and pendent branches; one with a white, broad, and acuminate leaf; one with brittle branches, and a blackish woolly leaf; one (B. saxátilis torminàlis) with an oblong leaf; and, lastly, the dwarf birch, probably the B. pùmila of Lodd. Cat. These varieties are recorded in Martyn's Miller; but, unless we are right in conjecturing B. pùmila to be the last, we have not seen any of them. Dr. Agardh mentions "three singular varieties with laciniated leaves (B. hybrida Manch) near Fahlun. (Gard. Mag., vol. xii. p. 63.) The birch varies so much from sted, that scarcely any limits can be given to the number of sorts that might be selected from a seed-bed. In extensive birch forests, also, whether in the rocky scenery of Sweden, the bogs in the north of Russia, or on the hills of Germany, full-grown trees may be seen, as various in their foliage and habit of growth as the young plants in seed-beds. For this reason, we are inclined to think that there are only two European species of birch, B. álba and B. nàna; and four American species, B. papyràcea, B. excélsa, B. lénta, and B. nigra. The Description. common birch, when of a tree-like size, is known, at first sight, by the silvery whiteness of its outer bark, the smallness of its leaves in comparison with those of other timber trees, and the lightness and airiness of its whole appearance. The tree, as comparedwith others, is of the middle size, seldom exceeding 50 feet in height, with a trunk of from 1 ft. to 18 in. in diameter, even in the most favourable situations. When drawn up in woods, however, in good soil, it has been known to attain the height of from 60 ft. to 80 ft., but never, in such situations, with a trunk of proportionate diameter. In the woods of Russia, Pallas observes, the birch is tall and erect, with a trunk not very thick; in the groves, the trunk is thicker, and the head more spreading; and, in the open fields, the trunk is short, the head broader than it is high, and the branches tortuous. The trunk is, in general, straight and cylindrical, without deformities and knots. The cuticle is white and scaly in trees from ten to thirteen years of age; but in old trees the trunk is covered with deep black clefts in its bark. The branches proceed chiefly from the summit, and are alternate, frequently subdivided, very pliant and flexible, and covered with a reddish brown or russet-coloured smooth bark, which, as well as the buds, is slightly impregnated with a resinous substance. Both the trunk and branches are occasionally subject to the production of excrescences; the former as large knots, and the latter as twiggy tufts resembling large birds' nests. These twiggy tufts are seldom found on the weeping variety, and abound most on trees of the common sort growing on boggy soil. They are most probably formed by the extravasation of the sap, occasioned by the puncture of some insect. The leaves are alternate, bright green, smooth, shining beneath, with the veins crossing like the meshes of a net; and the petioles are in. or more in length. The male catkins appear in autumn, on the ends of the twigs, but do not expand their flowers till the female catkins appear in spring. On young trees, and on old trees in particular situations, especially in damp boggy soil, the branches are erect; but in old trees, and in some young ones more than in others, they are pendulous, and hence the variety of that name. The roots extend themselves horizontally, and divide into a great number of rootlets and hair-like fibres at their extremities; but they never throw up suckers. The rate of growth is considerable when the tree is young; averaging from 18 in. to 2 ft. a year for the first 10 years; and young trees cut down to the ground often make shoots 8 ft. or 10 ft. long in one season. The duration of the birch is not great, the tree attaining maturity, in good soils, in from forty to fifty years; but, according to Hartig, seldom lasting in health till it attains a hundred years. Geography. The common birch is a native of the colder regions of the old Continent; and also, as we think (under the form of B. populifòlia, and other kinds, treated by botanists as species), throughout great part of North America. It is found in Asia, in Siberia, as far as the Altaic Mountains; and also in the Himalayas; but not in Africa. According to Pallas, the birch is more common than any other tree, throughout the whole of the Russian empire; being found in every wood and grove, from the Baltic Sea to the Eastern Ocean; prospering best in a moist alluvial soil (humoso-limosum); and, as it loves a moderate humidity, it always indicates land fit for the plough. In some parts of Russia, immense tracts are covered with this tree alone. In the neighbourhood of Moscow, it forms the prevailing tree in all the woods belonging to the country residences of the nobles, and it may be seen in the foreground of fig. 1551., which is a view of the Lake of Petrovskoyé, which, in 1814, when we made the sketch, was one of the most celebrated "English pleasure-grounds" in that part of the Russian empire. In Europe, Dr. Agardh observes, the region of the birch is bounded only by vegetation itself. It is found from Iceland to Mount Etna: in the Icelandic forests its limits are only those of vegetation; but on Mount Etna it is not higher than 5600 ft. above the level of the sea, its range being about 1000 ft. It is found on the whole line of the Apennines, in the kingdom of Naples, (where it commences at the height of 4761 ft. above the level of the sea,) and at the height of 6100 ft. forms little woods. (Comp. Bot. Mag., 1. p. 91.) It is also found on most of the high mountains of the south of Europe; on Mount Caucasus, in Bucharia, on the eastern shores of the Caspian Sea; in Kamtschatka, in forests at lat. 58° N.; in Dahuria, in Japan, and in West Greenland. (Dec.) Von Buch considers the birch to require a mean temperature of about 26° of Fahr. In Lapland, according to the same author, the line of birches is 1937 ft. below the line of eternal snow, and 802 ft. above the boundary of the Scotch pine. At Hosperdet, in a bay of the Icy Sea, the common birch is a low bush; but at Alten it becomes a lofty tree, forming woods. (Schouw in Gard. Mag., vol. xii. p. 60.) On the Alps, in Switzerland, it is never found at above the height of 4400 ft. (M. Alphonse De Candolle in Gard. Mag., vol. xii. p. 234.) B. álba appears in North America under the form of B. populifòlia, which, though by many botanists considered as a distinct species, yet we cannot help thinking is nothing more than a very distinct variety of the birch of Europe. (See No. 2.) B. pumila and B. glandulòsa, also found in North America, are, probably, nothing more than varieties of B. álba. In Britain and Ireland, it is found almost every where on mountains and in poor sandy soils; reaching to the height of 3500 ft. on some of the Highland mountains. According to Dr. Walker, the birch grows higher on the Highland mountains than any other tree except the mountain ash: but in this he must have been mistaken; because the extreme height at which the mountain ash is found in Forfarshire is, according to Watson, 2500 ft.; and the birch is found, in various places, 1000 ft. higher up the mountains. Some of the finest specimens of the weeping birch grow on the banks of rocky streams in North Wales. In England, the birch is supposed to have been once so plentiful in Berkshire as to have given the name to that county; though some suppose the name Berkshire to be a corruption of Bare-oak, or Berroc, shire. History. The common birch was known to the Greeks (see p. 18.) and to the Romans. According to Pliny and Plutarch, the celebrated books which Numa Pompilius composed 700 years before Christ, and which were buried with him on Mount Janiculum, were written on the bark of the birch tree. In the early days of Rome, the lictors had their fasces made of birch branches, which they carried before the magistrates to clear the way, beating the people back with the boughs. Pliny says that the birch was brought to Italy from Gaul; though, considering that it is a native of the Apennines, it is surprising that it should not have been known to the Romans as an indigenous tree. The birch was formerly used in England for ornamenting the houses during Rogation Week, in the same manner as holly is at Christmas. Gerard says the branches of the birch "serve well to the decking up of houses and banquetting roomes for places of pleasure, and beautifying the streetes in the Crosse, or Gang, Week, and such like." The Cross, or Gang, Week, Phillips tells us, was the same as Rogation Week; which was called Gang Week from the crowds, or gangs, of penitents going in that week to confession, before Whitsuntide. It was called Cross Week, from the crosses carried before the priests in the procession on Ascension Day; and Rogation Week, from the Latin verb rogo, to ask or pray. (Syl. Flor., i. p. 133.) Coles, writing in 1657, observes that, at this season, as he "rid through little Brickhill, in Buckinghamshire, every sign poste in the towne was bedecked with green birch." We have observed the same custom in Poland, at the same season; where, also, large boughs are fixed in the ground, against each side of the doors of the houses. The birch has been used as an instrument of correction at schools from the earliest ages Anciently, says Evelyn, "birch cudgels were used by the lictors, as now the gentler rods by our tyrannical pedagogues, for lighter faults." The sight of a birch tree, observes the writer of the article Birch in the Nouveau Du Hamel, "offers a vast subject of interesting meditation: but happy the man to whom its flexible pendent branches do not recall to mind that they were formerly instruments of punishment to him!" Gerard observes that, in his time, "schoolmasters and parents do terrify their children with rods made of birch.” The use of these rods, however, both in schools and private families, is now fast passing away, together with many other barbarous practices of our ancestors. At present, the tree is planted in Britain in poor soils, and in exposed situations, for sheltering others; in copses, for producing brooms, and for many other valuable purposes; and, in favourable soils and situations, as being ornamental. On the Continent, and more especially in France and Germany, it is extensively planted as a fuel tree, on the poorest soils; and, in good soils, as a nurse for hard-wooded and resinous trees. In the north of Russia, and in Sweden and Norway, the natural woods of birch form the principal supplies of fuel for large towns; and, in many places, also the principal timber for buildings, furniture, and rural implements. Properties and Uses. Naturally, the birch forms the food of various insects, when in leaf; and the buds and catkins, in the winter season, are eaten by numerous birds. The siskin, or aberdevine (Fringilla Spinus L.), feeds upon the seeds, which are its favourite food. The tree, when old, forms the habitat of various lichens, mosses, and fungi; particularly Dædàlea betùlina, and the fungus (Polyporus fomentàrius) that produces the moxa. The leaves and young shoots are also occasionally eaten by cattle, sheep, and swine, though they are not fond of them. Artificially, the birch recommends itself to the proprietor of woods and to planters, by the following qualities:-1st, By the lightness and multiplicity of its seeds, which it begins to produce at the age of six years; and which, being spread abroad on every side by the wind, give rise to a great number of young plants; thus producing a thick wood, without either care or labour. 2dly, By the rapidity of its growth, and the resistance which it makes to all the circumstances which usually destroy trees, and eradicate woods. 3dly, By its power of withstanding a great degree of both heat and cold. 4thly, By its suffering little from the bite of cattle, and being but seldom attacked by caterpillars, which are said only to have recourse to it after they have destroyed all the succulent leaves in the same forest; and which, consequently, being then nearly matured, can do it but little harm. 5thly, By its not requiring the shade or protection of other trees; while its own shade, from the lightness and thinness of its foliage, is extremely favourable to the growth of oaks, beeches, and, above all, the pine and fir tribe, which spring up under its protection with great vigour. Hence, the value of the birch as a nurse to hard-wooded trees, which it protects in their youth, but which destroy it when they acquire strength. 6thly, By its not injuring other trees with its roots, which run along the surface of the soil, and draw but very little nourishment from it. 7thly, By its succeeding almost every where, and improving poor soils by the deposition of its leaves. 8thly, By its furnishing useful products, such as spray for brooms, &c., a very short time after being planted. And, 9thly, by its producing a wood almost exclusively employed in Sweden, and other parts of the Continent, for smelting-furnaces; and in other cases where a bright clear flame is required. Though all these advantages, says the author of the article Bouleau, in the Dictionnaire des Eaux et Forêts, belong to the birch, we cannot place it in the first rank of forest trees; and the oak, the beech, and other trees of stately growth, are to be preferred to it in good soils: but the birch cannot be too strongly recommended for light and poor soils, sands, and chalks. In Prussia, he adds, the birch is planted every where; and it is considered to afford security against a dearth of fuel, and to insure the prosperity of the woods, by the dissemination of its seeds, which fill up every blank that occurs. The wood of the birch is white, shaded with red; of a medium durability in temperate climates, but lasting a long time when it is grown in the extreme north. The grain of the wood is intermediate between coarse and fine. It is easily worked while it is green; but it chips under the tool when dry. It weighs, when green, 65 lb. 6 oz.; half-dry, 56 lb. 6 oz.; and dry, 45 lb. 1 oz. The wood of old birch trees is harder than that of young trees, and it also weighs considerably more : for it appears, by the experiments of Hartig, that the wood of a tree of 60 years' growth, weighed, dry, 36 lb. 13 oz.; while that of a tree of 25 years' growth, in the same state of dryness, only weighed 35lb. 5oz. The wood soon rots when laid on the ground in heaps; and, therefore, immediately after the trees are felled, they ought to be drawn out of the wood, and taken into the timber-yard, where they can be exposed freely to the air. As fuel, birch wood occupies the 12th place among 21 different sorts; and is to the fuel of the beech as 13 is to 15: but, if the wood of the birch is to be compared with that of the beech, taken in the bulk, it is only as 12 to 15; because birch logs, not being so straight as those of the beech, do not pack so closely together. The wood gives a clear, bright, and ardent flame; and affords the kind of fuel most generally used in Sweden, Russia, and France, for smelting-furnaces. Its charcoal remains burning a long time; though, compared with that of the beech, its value is only as 144 to 16. The bark of the birch is remarkable for its durability, remaining uncorrupted for ages, even in situations exposed alternately to air and water, cold and moisture. Pallas refers, in proof of this, to the tombs near Jenisca, in Siberia; and to the vaults under the Kremlin, in Moscow. When Maupertuis travelled through Lapland, "to measure a degree of latitude, he was obliged to pass through vast forests, consisting entirely of birch. The soil, in some parts of these wastes, being very shallow, or very loose, the trees had |
