The British Cyclopaedia: Betulineæ. The Birch and Alder Tribe.

The British Cyclopaedia
of the arts, sciences, history, geography, literature, natural history and biography; copiously illustrated by engravings on wood and steel by eminent artists.
Edited by Charles F. Partington, professor of mechanical philosphy, author of various works on natural and experimental philosophy, &c., assisted by authors of eminence in the various departments of science.
Complete in ten volumes.
Volume VI.
Natural history.
London: WM. S. Orr and Co., Amen Corner, Paternoster Row.
A natural suborder of dicotyledonous vegetables, containing five genera and about fifty species. By some authors it is included along with the willow and oak tribe, under the Amentaceae. It is allied to the Cupuliferae. Its essential characters are:- flowers monoecious, growing in aments or catkins: stamens distinct, rarely united together; anthers two celled; ovary superior, two-celled; style single, or wanting; two stigmas; fruit membranaceous, inde hiscent; seeds pendulous, naked.

The plants of this order are trees or shrubs which shed their leaves every season, and which are found abundantly in the tenuperate and colder regions of the globe. Several species are found in the woods of Europe, North America, and the northern parts of Asia, and some are said to grow on the mountains of Peru and Colombia. The order contains many trees which are used in ornamenting landscapes, and which furnish valuable timber. They are propagated by layers and seeds.

The Betulineae, like the willows, contain much tannin, and possess astringent and tonic properties.

The principal genus is Betula or birch, whence the name of the order is derived. This genus contains numerous species which are highly interesting, and have been applied to important uses. Betula alba, common European or white birch, is an elegant tree familiar to every one. It is found in woods and in moist heathy mountainous situations in Britain. It grows in almost any kind of soil, moist, dry, gravelly, or chalky, and it is frequently seen issuing from the crevices of rocks. It endures the cold of northern regions well, and is found even at the seventieth degree of north latitude. It thrives well in Lapland, Norway, Sweden, and the northern parts of Russia. It is seldom met with farther south than the forty-fifth degree of latitude, unless upon lofty mountains. On the Alps it grows at an eleva tion considerably above that at which other trees thrive, but in such elevated situations it becomes very diminutive in size. In general it reaches a height of fifty or sixty feet, with a diameter of a foot and a half or two feet. It blooms early in spring, and sends forth pendulous catkins of flowers. The wood of the birch is hard, tough and white, and is used by wheel-wrights, turners, and carpenters, in the manufacture of various useful and ornamental articles. In some countries wooden shoes are made from it. The bark is thick, and is covered with a white scaly cuticle. It is astringent and bitter, and has been used in the cure of intermittent fever. On account of the resinous matter which it contains, it serves for torches to the inhabitants of the Alps. A decoction of the bark is used by the Laplanders in the preparation of reindeer skins. An empyreumatic oil also is obtained from it, which the Russians employ in tanning, and it is from this oil that Russia leather derives its peculiar odour. The inner part of the bark in its young state contains a quantity of fecula or starch, and from it the inhabitants of the northern regions make a sort of cake, which, along with smoked salt-fish, constitutes their food during the winter. The leaves of the birch are bitter, and have been used as a substitute for tea. They dye wool of a yellow colour. A decoction of them is said to possess vermifuge and diuretic qualities, and has been praised in calculous complaints and scurvy. A spirituous infusion of them is emloyed by the Russians and Swedes as an embrocation in rheumatism. By tapping the birch in spring, a sweetish sap is procured in great abundance, which by fermentation yields a sort of wine called birch-wine or mead. The tops and twigs of the birch are commonly used for brooms. Betula pendula, or the weeping birch, by some considered as a variety of the common birch, is the most graceful of the genus, and is easily recognised by its elegant drooping branches. Betula mana, or dwarf birch, is another European species found in northern climates, and approaching, in Norway and Lapland, very near the limits of perpetual snow. It is a small diminutive shrub, and is found on the Scottish mountains in considerable abundance. In summer, when the Laplander lives on the mountains, this plant furnishes his fuel, and, when covered with rein-deer skin, forms his bed. Its leaves dye a finer yellow than the common birch. Several species of birch are found in North America; of these the most important is the Betula nigra, or black birch, which furnishes a very hard and valuable wood. This wood when recently cut, has a rosy hue, which deepens by exposure to light. It receives a fine polish, and may be made to assume the appearance of mahogany: hence the tree is often called mountain mahogany. The twigs of the black birch, when bruised, give out a sweet scent. Betula papyracea is another useful North American species. From the wood of this species many articles of furniture are made, and its bark, which is white and indestructible, is used for the formation of canoes. On this account the tree is denominated the canoe birch. The name papyracea, or paper birch, is derived from the circumstance that the bark, when divided into thin sheets, is used as a substitute for paper. The red and yellow birch, two other American species, are not put to any particular use.

Another genus of this order is Alnus, or the alder. The alders in general grow in marshy, boggy situa tions by the sides of rivers, requiring black mould with plenty of moisture. They are often planted in places which cannot be drained. They are propa gated by layers.

Alnus glutinosa, or common alder, is a quick growing tree found in swamps and meadows in Europe, North America and the northern parts of Asia. It attains a height of fifty feet, and furnishes a compact wood capable of receiving a considerable polish. In France, wooden shoes, or sabots, are made from it, which are seasoned by fire before they are sold. From being able to resist the action of water, the wood is employed in the formation of durable water pipes, and in Holland it is used for piles, upon which buildings are erected in marshy places. It is said that piles of this nature were driven in under the old London bridge. The wood takes a black colour well, and can be made to resemble ebony. With green vitriol, it dyes wool of a black colour. It yields excellent charcoal, which is employed in making gunpowder. The juice of the alder is astringent, and the bark is used for tanning, and for detergent gargles.

Alnus incana, hoary alder, grows in several parts of Europe, and has received the name of cold alder, from not being found south of latitude sixty degrees. Alnus senulata, notch-leaved alder, and Alnus glauca, are two species found abundantly in North America.

Carpinus betulus, hornbeam, a tree of humble growth, and useful in the formation of hedges for shelter, belongs to the betulineae. It is found in woods and hedges in England, growing in damp, tenacious, meagre soil. It forms the principal part of the ancient forests on the north and east of London, such as Epping and Finchley. Its wood is hard and used for furniture, and its inner bark yields a yellow dye. Ostrya, another genus of the order, receives the name of hop-hornbeam, from its scaly catkins being similar to the hop. Ostrya Virginica is a small tree found in the shady woods of America. It supplies a hard heavy wood, called iron-wood or lever-wood.

Corylus is the fifth genus of this order. Corylus avellana, or hazel-nut tree, must be familiar to all, as furnishing the fruit commonly known by the name of filberts. This tree flowers early in spring, and its leaves do not appear till after the blossoms. Its wood is used for hoops, fishing-rods, walking-sticks, &c., and furnishes excellent charcoal for drawing. Squirrels live on the nuts, and an oil is prepared from them which is used by painters, and which is said to be efficacious against tooth-ach or worms. Corylus Americana, American hazel, yields also excellent nuts.

We have thus seen that the trees of this important order, are applied to many of the necessities of life. The wood of several of them is used for the construction of houses and vessels, in the works of the wheelwright, turner, and cabinet-maker, and as an article of fuel; the bark is manufactured into canoes and boxes, serves for the covering of houses, and supplies materials for dyeing and tanning; medicinal preparations, useful in various diseases, are obtained from several species; from some a nutritious article of diet is procured, while from others a sap exudes which constitutes a grateful and refreshing beverage.

Ei kommentteja :