the Birch-tree: A genus of the te-trandria order, belonging to the monoecea clas of plants; and in the natural method ranking under the 5th order, Anemoneae. The calyx of the male is monophyllous, trifid, and triflorous; and the corolla is parted into four segments: The female calyx is monophyllous, trifid, and biflorous: The seeds have a membranaceous wing on both sides.

Species: 1. The alba, or common birch-tree, is so well known as to need no description. It is in general of a humble growth; however, in a foil and situation it affects, it will rise to a great height, and swell to a considerable size. There is a spruceness in its general appearance in summer; and in winter its bark sometimes exhibits, in its variegations of red and white, no inelegant object. Were it not for its being so commonly seen upon poor foils, and in bleak inhospitable situations, as well as for the mean and degrading purposes to which it is universally put, the birch would have some claim to being admitted to a place among the ornamentals. 2. The ana, or dwarf-birch, with roundish leaves, grows naturally in the northern parts of Europe and on the Alps. It seldom rises above two or three feet high, having slender branches garnished with round leaves, but seldom produces flowers here. It is preserved in some curious gardens for the sake of variety, but is a plant of no use. 3. The lenta, or Canada birch, grows to a timber-tree of 60 or more feet in height. The leaves are heart-shaped, oblong, smooth, of a thin consistence, pointed, and very sharply serrated. They differ in colour; and the varieties of this species go by the names of, 1. Dusky Canada birch; 2. White-paper birch; 3. Poplar-leaved Canada birch; 4. Low-growing Canada birch, &c.—4. The nigra, or black Virginia birch-tree, will grow to upwards of 60 feet in height. The branches are spotted, and more sparingly set in the trees than the common sorts. The leaves are broader, grow on long footstalks, and add a dignity to the appearance of the tree; and as it is naturally of upright and swift growth, and arrives at so great a magnitude, Hanbury thinks it ought to have a share among our forest-trees, and to be planted for standards in open places, as well as to be joined with other trees of its own growth in plantations more immediately designed for relaxation and pleasure. There are several varieties of this species, differing in the colour, size of the leaves, and shoots; all of which have names given them by nurserymen, who propagate the different sorts for sale; such as, 1. The broad-leaved Virginian birch; 2. The poplar-leaved birch; 3. The paper birch; 4. The brown birch, &c.—5. The alnus, or alder-tree, will grow to a large timber tree. Like the birch, it suffers, as an ornamental, from an association of ideas; we not only see it very common, but we see it in low, dreary, dirty situations; nevertheless, if the alder be suffered to form its own head in an open advantageous situation, it is by no means an unsightly tree: in Stow Gardens, in what is called the old part, there are some very fine ones; and in coming round from the house by the road leading to Buckingham, there is one which is truly ornamental. Hacked and disfigured in the manner in which alders in general are, they have but little effect in doing away the ungratefulness of a swamp; but if they were suffered to rise in groups and singlets, open enough to have room to form their full tops, and close enough to hide sufficiently the unseeliness of the surface, even a moor or a morass seen from a distance might be rendered an agreeable object. Wherever the soil is or can be made palatable, the alder should by no means be permitted to gain a footing. Its suckers and seedlings poison the herbage; and it is a fact well known to the observant husbandman, that the roots of the alder have a peculiar property of rendering the soil they grow in more moist and rotten than it would be if not occupied by this aqueous plant. Plantations of alders should therefore be confined to swampy, low, unpasturable places; except when they are made for the purposes of ornament; and in this case the native species ought to give place to its more ornamental varieties, of which Hanbury makes five; namely, 1. The long-leaved alder; 2. The white alder; 3. The black alder; 4. The hoary-leaved alder; 5. The dwarf alder.

Culture. The first sort is easily propagated; it may be raised either from seeds or layering; and it will flourish in almost any foil and situation. The method of propagating the foreign sorts of birch is, 1. From seeds. We receive the seeds from America, where they are natives; and if we sow them in beds of fine mould, covering them over about a quarter of an inch deep, they will readily grow. During the time they are in the seminary, they must be constantly weeded, watered in dry weather, and when they are one or two years old, according to their strength, they should be planted in the nursery in rows in the usual manner. Weeding must always be observed in summer, and digging between the rows in winter; and when the plants are about a yard or four feet high, they will be of a good size to be planted out for the shrubbery-quarters. A part, therefore, may be then taken up for such purposes; whilst the remainder may be left to grow for standards, to answer such other purposes as may be wanted. 2. These trees may also be propagated by layers; and this is the way to continue the peculiarities in the varieties of the different sorts. A sufficient number of plants should be procured for this purpose, and set on a spot of double-dug ground, three yards distance from each other. The year following, if they have made no young shoots, they should be headed to within half a foot of the ground, to form the stools, which will then shoot vigorously the summer following; and in the autumn the young shoots should be plashed near the stools, and the tender twigs layered near their ends. They will then strike root, and become good plants by the autumn following; whilst fresh twigs will have sprung up from the stools, to be ready for the same operation. The layers, therefore, should be taken up, and the operation performed afresh. If the plants designed for stools have made good shoots the first year, they need not be headed down, but plashed near the ground, and all the young twigs layered. Thus may an immediate crop be raised this way; whilst young... young shoots will spring out in great plenty below the plashed part, in order for layering the succeeding year. This work, therefore, may be repeated every autumn or winter; when some of the strongest layers may be planted out, if they are immediately wanted; whilst the others may be removed into the nursery, to grow to be stronger plants, before they are removed to their defined habitations. 3. Cuttings also, if set in a moist shady border the beginning of October, will frequently grow: But as this is not a sure method, and as these trees are so easily propagated by layers, it hardly deserves to be put in practice.

The propagation of the alder, like that of the other aquatic natives, is very easy: it may be raised either from suckers, from cuttings, or by layering; and no doubt from seed, though this mode of propagation is seldom practised in this country. Evelyn mentions a peculiar method of raising this tree from cuttings or truncheons, which he calls the Jersey manner: he says, "I received it from a most ingenious gentleman of that country: it is, to take truncheons of two or three feet long at the beginning of the winter, and to bind them in faggots, and place the ends of them in water till towards the spring, by which season they will have contracted a swelling spine or knur about that part, which being set does (like the gnetum-moil apple-tree) never fail of growing and striking root." Millar recommends truncheons of three feet long, two feet of which to be thrust into the ground. Hanbury says that truncheons are uncertain, and strongly recommends layering; which for preserving the varieties, as well as for ornamental plantations of alders in general, is the best method.

Uses. In some of the northern parts of Europe the wood of the white birch is much used for making carriages and wheels, being hard and of long duration. In France it is generally used for making wooden shoes, and in Britain for making women's shoe-heels, packing-boxes, brooms, hoops, &c. It also makes very good fuel, and is planted along with hazel to make charcoal for forges. The bark of the birch tree seems in a manner incorruptible. In Sweden the houses are covered with it, and it lasts many years. It frequently happens that the wood is entirely rotten, when the bark is perfectly sound and good. In Kamtschatka it is used for making drinking cups. It abounds with a resinous matter, to which its durability is certainly owing. In consequence of this matter, it is highly inflammable; and in the northern countries torches are made of this bark sliced and twisted together. The bark itself consists of two different substances; a thick brittle brownish red one; and several very thin, smooth, white, transparent membranes. In these last the inflammable property resides. The thick brittle part is less resinous, and has a roughish taste. It has been thought to possess some medical virtues, but concerning these experience has as yet determined nothing certain. Upon deeply wounding or boring the trunk of the tree in the beginning of spring, a sweetish juice issues forth, sometimes, as is said, in a large quantity as to equal the weight of the whole tree and root; one branch will bleed a gallon or more in a day. This juice is recommended in scorbustic disorders, and other foulnesses of the blood; its most sensible effect is to promote the urinary discharge. By proper fermentation with the addition of sugar, this juice makes a pleasant wine. The bark of the Canada birch is very light, tough, and durable; and the inhabitants of America use it for canoes. Notwithstanding these uses to which the birch is applicable when already in possession, the planting of it is not recommended, except in bleak and barren situations where no other tree will thrive, and except as a screen and guardian to nurse up and defend from chilling blasts plants of greater value.

The alder tree flourishes best in low marshy situations, in which it is frequently planted to make hedges, and is also of great use for securing the banks of rivers. Grass grows well beneath its shade: the wood is soft and brittle; but lasts a long time under water, and consequently is of use for pipes, and to lay under the foundations of buildings situated upon bogs. Women's shoe heels, ploughman's clogs, and various articles of the turner kind, are made of it. The bark gives a red colour, and with the addition of copperas a black: it is chiefly used by fishermen to stain their nets. In the Highlands of Scotland near Dundonnell, Mr Pennant says, the boughs cut in the summer, spread over the fields, and left to rot in the winter, are found to answer as a manure. In March, the ground is cleared of the undecayed parts, and then ploughed. The fresh gathered leaves are covered with a glutinous liquor; and some people strew them on their floors to kill fleas. These insects are said to be entangled in the glutinous liquor of the leaves, as birds are by birdlime. The whole plant is astringent, and its bark has been recommended in intermittent fevers. The bark of the black berry-bearing alder is said to be the most certain purge for horned cattle in obstinate colications of the bowels. Horses, cows, goats, and sheep, eat the leaves of all the species of betula; but swine refuse them. When eaten by cows, they are said greatly to increase the quantity of the milk.