15. P. CA'NDICANS Ait. The whitish-leaved balsam-bearing, or Ontario, Poplar. Identification. Ait. Hort. Kew., ed. 1., 3. p. 406., ed. 2., 5. p. 397.; Willd. Arb., 231., Sp. Pl., 806. ; Michx. Arb.; North Amer. Sylva, 2. p. 239. t. 98. f. 2.; Pursh Fl. Amer. Sept., 2. p. 618.; Spreng. Syst. Veg., 2. p. 244. Synonymes. P. macrophylla Lindl. in Encyc. of Plants, p. 840., and Lodd. Cat., 1836; P. latifòlia Manch Meth., p. 338.; P. ontariénsis Desf. Hort. Par., and Lodd. Cat., 1836; P. cordata Lodd. Cat., 1836; P. canadensis Monch Weissenst., 81., but not of Michx, which is P. lævigata Willd.; Balm of Gilead Tree, Boston, North Amer. ; Peuplier liard, Canada; Peuplier à Feuilles vernissées, Fr. The Sexes. The male is in the London Horticultural Society's Garden; the female is in the Duke of Wellington's garden at Apsley House, London. Engravings. Catesb. Car., 1. t. 34.; Michx. Arb.; Michx. North Amer. Sylva, 2. t. 98. f. 2. ; and our fig. 1537. Spec. Char., &c. Shoot round. Bud very gummy. Stipules gummy. Petiole compressed in its upper part, hairy in many instances. Disk of leaf heart-shaped at the base, ovate, acuminate; serrated with blunt, unequal teeth; 3-nerved; deep green on the upper surface, whitish on the under one, on which the veins appear reticulate. Inflorescence similar to that of P. balsamífera (Michx. jun., Pursh, Spreng., and obs.) The disk of the leaf is thrice as large as that of P. balsamífera. (Michx. jun.) A tree, attaining the height of 40 ft. or 50 ft., with a trunk 18 in. or 20 in. in diameter, in the states of Rhode Island, Massachusetts, and New Hampshire; flowering, with the balsam poplar, in March. It was introduced into England in 1772, and is frequent in gardens. Description, &c. The Ontario poplar bears a close general resemblance to the balsam poplar: it has the rigid fastigiate habit of that tree, its fine fragrance, and its property of throwing up numerous suckers; but it differs from it, in having very large heart-shaped leaves, and in attaining a larger size, both in its native country, and in British gardens. The buds are covered with the same balsamic substance as those of P. balsamífera; and the leaves are of the same fine yellow colour in spring, and, like those of the balsam poplar, preserve, at all stages of their growth, the same shape. The foliage, when mature, is tufted, and of a dark green; the disposition of the branches is somewhat rigid and irregular; which last circumstance prevents the foliage from massing well together, and gives the tree rather an inelegant appearance. The trunk is covered with a smooth greenish bark, which becomes darker with age; the 1537 wood is soft; and, like that of the balsam poplar, is chiefly valuable for producing potash. Michaux never found the tree in forests in America, nor was he able to discover where it was indigenous; but he found it growing commonly before houses, both in the towns and country. Pursh mentions New England as the place where he had seen it in a living state. In British gardens, it has very frequently been confounded with the balsam poplar; and the same thing, Bosc informs us, often happens in France. Bosc strongly recommends this tree for its shade, and the fragrance with which it perfumes the air in spring. It is readily propagated by cuttings or suckers, but will not attain a large size unless on rich soil near water; though, as the roots creep along the surface, the soil need not be deep. Statistics. In England, in Buckinghamshire, at Temple House, 40 years planted, it is 70 ft. high; the diameter of the trunk 2 ft., and of the head 30 ft.; in Durham, at Southend, 7 years planted, it is 20 ft. high; in Hertfordshire, at Cheshunt, 18 years planted, it is 45 ft. high; in Nottinghamshire, at Clumber Park, 10 years planted, it is 48 ft. high; in Warwickshire, at Whitley Abbey, 7 years planted, it is 24 ft. high. In Scotland, near Edinburgh, at the Experimental Garden, Inverleith, 9 years planted, it is 23 ft. high; in Fifeshire, at Danibristle Park, 9 years planted, it is 23 ft. high; in Stirlingshire, at Callender Park, 16 years planted, it is 70 ft. high In Ireland, at Dublin, in the Glasnevin Botanic Garden, 30 years planted, it is 30 ft. high. In Germany, at Vienna, in the garden of Baron Loudon, 30 years old, it is 24 ft. high. Price of plants as in P. balsamífera. CHAP. CIV. OF THE HARDY LIGNEOUS PLANTS OF THE ORDER BETULA CEÆ. THESE are included in two genera, the characters of which are thus given by Smith: A'LNUS Tourn. Barren flowers numerous, aggregate, in a loose cylindrical catkin, imbricated every way. Calyx a permanent wedge-shaped scale, 3-flowered, with 2 very minute lateral scales. Corolla composed of 3 equal florets, attached to the inner side of every scale, each of one petal, in 4 deep, equal, ovate, obtuse segments. Filaments 4, from the tube of the corolla, shorter than its segments, and opposite to them. Anthers of 2 round lobes.-Fertile flowers fewer, aggregate, in an oval firm catkin, imbricated every way. Calyx a permanent, wedge-shaped scale, 2-flowered. Corolla none. Germen compressed, of 2 cells. Styles 2, parallel, tapering, a little prominent, deciduous. Stigma simple. Nut ovate, bony, compressed, angular, without wings, of 2 cells. Kernels solitary, ovate, acute.-Trees, with leaves alternate, stalked, simple, wavy or cut, deciduous, with twin deciduous stipules. Catkins terminal, panicled, pendulous, earlier than the foliage. (Eng. Fl., iv. p. 134.) Natives of Europe and North America. BE'TULA Tourn. Barren flowers. Catkin cylindrical, lax, imbricated all round with ternate concave scales; the middle one largest, ovate. rolla none. Filaments 10-12, shorter than the middle scale, to which they are attached. Anthers roundish, 2-lobed.-Fertile flowers. Catkin similar, but more dense; scales horizontal, peltate, dilated outwards, 3lobed, 3-flowered. Corolla none. Germen compressed, bordered, of 2 cells. Styles 2, awl-shaped, downy. Stigma simple. Nut oblong, deciduous, winged at each side, of one cell, with a solitary kernel.-Trees or shrubs, very hardy, with round slender branches; scattered, stalked, simple, serrated, deciduous leaves; and a hard, often veiny, wood. Bark, in several species, of many fine, soft, membranous layers. (Eng. Fl., iv. p. 153.) Natives of Europe, North America, and Asia. Co The alder and the birch were made separate genera by Tournefort, and by Linnæus also, in his earlier works; but he afterwards united both genera into one, under the name of Bétulus. Modern botanists, for the most part, follow Tournefort; and the following are the distinctive characteristics of his two genera:-In Bétula, the female catkins are cylindrical, solitary, on simple peduncles, and bear their seeds furnished with a membrane on each side. In A'lnus, the female catkins are oval; and they are borne on a branchy peduncle, containing seeds which are not bordered with membranes. As secondary characteristics, the birches prefer dry places, and the alders moist situations. All the known species of alder may be reduced to three or four; and all the species of birch which are hardy in England to four or five. Most of the species of both genera flower and fruit freely in the climate of London. GENUS I. A'LNUS Tourn. THE ALDER. Lin. Syst. Mono'cia Tetrándria. Identification. Tourn., t. 359.; Willd. Sp. Pl., 4. p. 334.; Hall. Hist., 2. p. 300.; Comp., ed. 4., p. 176.; Gærtn., t. 90. Synonymes. Betula species Lin.; Aune, Fr.; Erle, Ger.; Ontano, Ital.; Aliso, Span. Derivation. From al, near, and lan, the edge of a river, Celtic; in reference to its habitat: from the Hebrew, alon, an oak: or, according to others, from alitur amne, it thrives by the river. Description, &c. Trees, rarely exceeding the middle size; and some so low as to be considered shrubs. With the exception of A. glutinosa laciniàta and A. cordifòlia, the species are not very ornamental; nor is the timber of great value, except for the charcoal which may be made from it. All the species prefer a moist soil, or one in the vicinity of water. A. glutinosa ripens seeds freely, as do most of the other sorts; but all the latter are generally propagated by layers. The only truly distinct species appear to us to be, A. glutinosa, A. cordifolia, A. incàna, A. oblongata, and A. víridis; which last seems an intermediate species, or connecting link, between A'lnus and Bétula. 1. A. GLUTINO'SA Gartn. The glutinous, or common, Alder. Identification. Gærtn., 2. p. 54.; Willd. Sp. Pl., 4. p. 334. Comp., ed. 4., p. 155.; Hook. Lond., t. 59., Scot., 271.; Hoss. Anleit., 186.; Lodd. Cat., ed. 1836. Synonymes. Bétulus Alnus Lin. Sp. Pl., 1394. a, Fl. Br., 1013., Eng. Bot., 21. t. 1508.; B. emar. ginata Ehrh. Arb., 9.; Alnus Raii Syn., 442.; Aune, Fr. gemeine Else, or Elser, or schwartz Erle, Ger.; Elsenboom, Dutch; Alno, or Ontano, Ital.; Aliso, or Alamo nigro, Span. Engravings. Eng. Bot., t. 1508.; Hunt. Evel. Syl., 240. f.; Ger. Emac., 1477. f.; Lob. Ic., 2. 191. f.; Loes. Pruss., t. 1.; Dalech. Hist., 97. f.; our fig. 1540.; and the plate of this species in our last Volume. Spec. Char., &c. Leaves roundish, wedge-shaped, wavy, serrated, glutinous, rather abrupt; downy at the branching of the veins beneath. (Eng. Fl., iv. p. 131.) A tree, from 30 ft. to 60 ft. high; a native of Europe, from Lapland to Gibraltar; and of Asia, from the White Sea to Mount Caucasus; and, also, of the north of Africa; flowering, in Britain, in March and April. Varieties. A. g. 2 emarginata Willd. Baum., p. 19., St. Germain, where the stool still remains from which all the nurseries of Paris have been supplied with plants, and, probably, all Europe. A. g. 4 quercifolia Willd., 1. c., Lodd. Cat., ed. 1836.-Leaves sinuated, with the lobes obtuse. A. g. 5 oxyacanthafolia; A. oxyacanthæfòlia Lodd. Cat., ed. 1836; and our fig. 1539.-Leaves sinuated and lobed; smaller than those of the preceding variety, and somewhat resembling those of the common hawthorn. A. g. 6 macrocárpa; A. macrocarpa Lodd. Cat., 1836; has the leaves and fruit rather larger than those of the species, and is also of more vigorous growth. A. g. 7 foliis variegatis Hort. has the leaves variegated. Other Varieties. There are some other names applied to plants in the collection of Messrs. Loddiges, which, we think, can only be considered as varieties of A. glutinòsa; or, perhaps, of A. incàna; but the plants are so small, that we are unable to determine whether they are sufficiently distinct to be worth recording. Among these names are, A. nigra, A. rùbra, A. plicata, and A. undulata. A. rùbra is said to be a native of the Island of Sitcha. (Annal. des Scien. Nat., 3. p. 237.) Some of the sorts treated as species we think only varieties, as we have indicated by putting the letter g. in parentheses. Description. The alder, in a wild state, even in favourable situations, is seldom seen higher than 40 ft. or 50 ft.; but in uncultivated grounds, and in good soil near water, it will attain the height of 50 ft. or 60 ft., and upwards. This is not only the case with the species, but with the variety A. g. laciniata, which forms a handsome pyramidal tree; which, at Syon, has attained the height of 63 ft., and at Woburn Farm, near Chertsey, is still higher. The bark of the common alder, in oldish trees, is nearly black, and full of clefts; the colour of the wood is white before the tree is cut down; but, immediately on being cut, the surface of the wound becomes of a deep red; soon fading, however, into the pale flesh-colour, which the whole of the wood of this tree, when cut down, takes when dry, and retains ever afterwards. The wood is homogeneous, tender, and without much tenacity. The branches, when they are young, and the tree is in a state of vigorous growth, have a triangular form; but, when mature, they are round. The bark, at the rising of the sap, separates from the wood with very great facility. The leaves, when in the bud, are folded in the manner of a fan, very glutinous, and completely enclosed by two oblong stipules of a whitish green. They are from 3 in. to 4 in. long, and nearly as broad. The petiole is about 1 in. long, and prolonged on the disk of the leaf, in the form of a very prominent nerve on the under side, from which proceed to the right and left other prominent nerves, in each of the axils formed by which is a little tuft of cottony hair. The characteristics of the leaves of this species, as compared with those of other species of the genus, and especially of A. incàna, is, that they are always rounded at the summit, and never pointed; though this distinction does not hold good when applied to some of the varieties, such as A. g. laciniata. The leaves are of a deep dark green; and both the young shoots and leaves are covered with a glutinous substance, more especially in the early part of summer. The male catkins are cylindrical, like those of the birch, and appear in the autumn; while the female ones, which are on branched footstalks, are of a short conical form, like a small fir cone, and are produced in spring along with the leaves. On Mount Caucasus, Pallas informs us, the female catkins come out about the end of February; but, in the north of Russia, in March and April. The rate of growth of the alder, in a favourable soil and situation, is about 2 ft. or 3 ft. a year for four or five years; so that a tree 10 years planted will frequently attain the height of 20 ft. or 25 ft.; and at 60 years the tree is supposed to have arrived at maturity. The roots are creeping; and sometimes, but rarely, they throw up suckers. The shade and fallen leaves of this tree are not injurious to grass. Geography, History, &c. The common alder is the most aquatic of European trees, being found in wet swampy grounds, throughout the whole of Europe, in situations too moist for even the willow and the poplar. In meadows, and by river sides in the plains, it becomes a considerable tree; but on mountains, and in the most northerly parts of Sweden, it diminishes to a shrub. It is found in the west, east, and north of Asia and in the north of Africa. According to Pursh, the common alder is also a native of North America; in the interior of Canada, and on the north-west coast. The alder was known to Homer and Theophrastus. (See p. 18.) According to Virgil, it formed the first material for boats; and Lucan recommends it as a wood proper for ship-building. Virgil describes the proper situation for it, as on the margin of still waters; and Vitruvius recommends the wood for piles, stating that the city of Ravenna was built on it. Aristotle mentions that the alder was generally barren in Greece, and only fertile in the island of Crete; but it may be doubted whether he alludes to the same tree. In the time of Theophrastus, the bark was used for dyeing leather; and, in the days of Pliny, the wood was employed for piles, which he calls "eternal;" and for pipes, for conveying water under ground, as it is at present. The same author states that the tree was planted along the banks of rivers, to prevent them, by its numerous roots and suckers, from being washed away during extraordinary floods. Evelyn tells us that the celebrated bridge of the Rialto, at Venice, was built on piles of this tree. It is still extensively used in Flanders and Holland, for the purpose of forming piles. Boutcher, writing in 1780, informs us that, between 1730 and 1750, "vast quantities of alder plants were brought from Holland to Scotland, at a considerable price, and unhappily for the owners, planted in large tracts of moist land, from which no returns suitable to the labour and expense had been received." He adds that he would greatly have preferred "poplars and abeles." (Treatise, &c., p. 111.) 1541 Properties and Uses. Naturally, the leaves of the alder afford food to the larvæ of different species of moths, and other insects; and the leaves and young shoots are eaten by horses, cows, goats, and sheep, though they are not fond of them; and they are refused by swine. Among the lepidopterous insects may be mentioned several species of the genus Hipparchia Fab. Satúrnia Schrank. (See Magazine of Natural History, vol. viii. p. 210., and vol. v. p. 251.) Clytus álni Fab., a coleopterous insect, is common in the trunks of old alder trees. C. Arìetis Fab., Cerambyx Arietis L., Sam. pl. 2. f. 25., and our fig. 1541., is also common. The tongues of horses feeding upon the alder, Linnæus observes, are turned black; and, on that account, it is supposed by some persons to be unwholesome for them. The uses to which the alder has been applied by man are various. The wood, though soft, is of great durability in water. It weighs, when green, 62 lb. 6 oz.; half-dry, 48 lb. 8 oz.; and quite dry, 39 lb. 4 oz., per cubic foot; thus losing above a third of its weight by drying, while it shrinks about a twelfth part of its bulk. In the Dictionnaire des Eaux et Forêts, the wood is said to be unchangeable either in water or earth. It is used for all the various purposes to which soft homogeneous woods are generally applied; viz. for turnery, sculpture, and cabinet-making; for wooden vessels, such as basins, plates, and kneading-troughs; for sabots, wooden soles to shoes and pattens, clogs for women, and similar purposes. In France, sabots made of alder wood are smoked, to render them hard and impervious to the larva of the beetle which attacks that wood. The French, and also the Highlanders, are said to make light chairs of the wood of this tree, which have the colour, though they have not the grain, of mahogany. Sir Thomas Dick Lauder, speaking of the wood, says, "It is extremely valuable, even when of a small size, for cutting up into herring-barrel staves; and thus whole banks, in Scotland, have been denuded every year of this species of timber. The old trees, which are full of knots, cut up into planks, have all the beauty of the curled maple, with the advantage of presenting a deep, rich, reddish tint; and, in this state, they make most beautiful tables. It must be remembered, however, that the alder timber is liable to be perforated by a small beetle; it should, therefore, if possible, be prepared by immersing the logs in a large hole dug in a peat moss, and impregnating the water of the hole with a quantity of lime. If this be done for |