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OAK (O. Eng., (lc)
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See also:OAK (O. Eng., (lc) , a word found, variously modified, in all Germanic See also:languages, and applied to See also:plants of the genus Quercus, natural See also:order Fagaceae (Cupul'ferae of de See also:Candolle), including some of the most important See also:timber trees of the See also:north temperate See also:zone. All the See also:species are arborescent or shrubby, varying in See also:size from the most stately of See also:forest trees to the dwarfish See also:bush. Monoecious, and bearing their male See also:flowers in catkins, they are readily distinguished from the See also:rest of the catkin-bearing• treesby their See also:peculiar See also:fruit, an See also:acorn or See also:nut, enclosed at the See also:base in a woody See also:cup, formed by the consolidation of numerous involucral bracts See also:developed beneath the fertile See also:flower, simultaneously with a cup-like expansion of the thalamus, to which the bracteal scales are more or less adherent. The ovary, three-celled at first, but becoming one-celled and one-seeded by See also:abortion, is surmounted by an inconspicuous perianth with six small See also:teeth. The male flowers are in small clusters on the usually slender and pendent stalk, forming an interrupted catkin; the stamens vary in number, usually six to twelve. The alternate leaves are more or less deeply sinuated or cut in many species, but in some of the See also:deciduous and many of the See also:evergreen kinds are nearly or quite entire on the margin. The oaks are widely distributed over the temperate parts of See also:Europe, See also:Asia, North See also:Africa and North See also:America. In the western hemisphere they range along the Mexican See also:highlands and the See also:Andes far into the tropics, while in the Old See also:World the genus, well represented in the Himalayas and the hills of See also:China, exists likewise in the See also:peninsula of Malacca, in the See also:Indian See also:Archipelago and Malaya to the Philippine Islands and See also:Borneo. On the From Kotschy, See also:Die Eicheu Europas, See also:Vienna, I862, See also:Plate XXXI[, FIG. 1. —Flowers of Oak (Quercus). a, See also:Diagram of male flower. d, Male flowers of Q. sessiliflora, b, Diagram of See also:female flower. much enlarged. c, Female flowers of Q. e, Female flowers of Q. sessili- pedunculata, slightly en- See also:flora, after fertilization, en- larged. larged. mountains of Europe and North America they grow only at moderate elevations, and none approach the See also:arctic circle. The multitude of species and the many intermediate forms render their exact See also:limitation difficult, but those presenting sufficiently marked characters to justify specific See also:rank probably approach 300 in number. The well-known Q. Robur, one of the most valued of the genus, and the most celebrated in See also:history and myth, may be taken as a type of the oaks with sinuated leaves. Though known in See also:England, where it is the only . indigenous species, as the See also:British oak, it is a native of most of the milder parts of Europe, extending from the shores of the See also:Atlantic to the Ural; its most See also:northern limit is attained in See also:Norway, where it is found See also:wild up to See also:lat. 63°, and near the Lindesnaes forms See also:woods of some extent, the trees occasionally acquiring a considerable size. In western See also:Russia it flourishes in lat. 6o°, but on the slope of the Ural the 56th parallel is about its utmost range. Its northern limit nearly coincides with that of successful See also:wheat cultivation. Southwards it extends to See also:Sardinia, See also:Sicily and the Morea. In Asia it is found on the See also:Caucasus, but does not pass the Ural See also:ridge into See also:Siberia. In See also:Britain and in most of its See also:Continental habitats two varieties exist, regarded by many as distinct species: one, Q. pedunculata, has the acorns, generally two or more together, on See also:long stalks, and the leaves nearly sessile; while in the other, Q. sessiliflora, the fruit is without or with a very See also:short peduncle, and the leaves are furnished with well-developed petioles. But,
though the extreme forms of these varieties are very dissimilar, innumerable modifications are found between them; hence it is more convenient to regard them as at most sub-species of Q. Robur. The British oak is one of the largest trees of the genus, though old specimens are often more remarkable for the See also:great size of the See also:trunk and See also:main boughs than for very lofty growth. The spreading branches have a tendency to assume a tortuous See also:form, owing to the central shoots becoming abortive, and the growth thus being continued laterally, causing a zigzag development, more exaggerated in old trees and those See also:standing in
From Kotschy, op. cit. Plate See also:XXVII.
exposed situations; to this peculiarity the picturesque aspect of See also:ancient oaks is largely due. When standing in dense woods the trees are rather straight and formal in See also:early growth, especially the'sessile-fruited kinds, and the gnarled See also:character traditionally assigned to the oak applies chiefly to its advanced See also:age. The broad deeply-sinuated leaves with See also:blunt rounded lobes are of a peculiar yellowish See also:colour when the buds unfold in May, but assume a more decided See also:green towards midsummer, and eventually become rather dark in tint; they do not See also:change to their See also: Vast oak forests still covered the greater See also:part of England and central Europe in the earlier historic See also:period; and, though they have been gradually cleared in the progress of cultivation, oak is yet the prevailing See also:tree in most of the woods of See also:France, See also:Germany and See also:southern Russia, while in England the coppices and the few fragments of natural forest yet See also:left are mainly composed of this species. The pedunculated variety is most abundant in the southern and midland counties, the sessile-fruited kinds in the northern parts and in See also:Wales, especially in upland districts; the straighter growth and abundant acorns of this sub-species have led to its extensive introduction into plantations. The name of " durmast " oak, originally given to a dark-fruited variety of Q. sessiliflora in the New Forest, has been adopted by foresters as a See also:general See also:term for this See also:kind of oak; it seems to be the most prevalent form in Germany and in the See also:south of Europe. Many of the ancient oaks that remain in England may date from Saxon times, and some perhaps from an earlier period; the growth of trees after the trunk has become hollow is extremely slow, and the age of such See also:venerable giants only See also:matter of vague surmise. The celebrated Newland oak in See also:Gloucestershire, known for centuries as " the great oak," was by the latest measurement 471 ft. in girth at 5 ft. from the ground. The Cowthorpe oak, standing (a ruin) near Wetherby in See also:Yorkshire, at the same height See also:measures 381 ft., and seems to have been of no smaller dimensions when describedby See also:Evelyn two centuries ago; like most of the See also:giant oaks of Britain, it is of the pedunculate variety. The See also:wood of the British oak, when grown in perfection, is the most valuable produced in temperate climates. The See also:heart-wood varies in colour from dark brown to See also:pale yellow+shbrown; hard, See also:close-grained, and little liable to split accidentally, it is, for a hard wood, easy to See also:work. Under See also:water it excels most woods in durability, and none stand better alternate exposure to drought and moisture, while under See also:cover it is nearly indestructible as long as dry-rot is prevented by See also:free See also:admission of See also:air. Its See also:weight varies from 48 to about 55lb the cubic See also:foot, but in very hard slowly-grown trunks sometimes approaches 6o lb. The See also:sap-wood is lighter and much more perishable, but is of value for many purposes of rural See also:economy. The relative qualities of the two varieties have been the frequent subject of debate, the See also:balance of See also:practical testimony seeming to establish the superiority of Q. pedunculata as far as durability in water is concerned; but when grown under favourable circumstances the sessile oak is certainly equally lasting if kept dry. The wood of the durmast oak is commonly heavier and of a darker colour, hence the other is sometimes called by woodmen the See also: It is frequently raised at once by See also:sowing the acorns on the ground where the trees are required, the fruit being gathered in the autumn as soon as shed, and perfectly ripe seeds selected; but the See also:risk of destruction by mice and other See also:vermin is so great that transplanting from a nursery-See also:bed is in most cases to be preferred. The acorns should be sown in See also:November on well-prepared ground, and covered to a See also:depth of t' or 2 in.; the seeds germinate in the spring, and the seedlings are usually transplanted when one or two years old to nursery-beds, where they are allowed to grow from two to four years, till required for the See also:plantation. Some authorities recommend the tap-roots to be cut in the second See also:year, with the view of increasing the See also:ball of fibre; but, if the trees are removed from the See also:seed-bed sufficiently early, the See also:root is best left to its natural development. The oak requires shelter in the early stages of growth; in England the Scotch See also:pine is thought best for this purpose, though Norway spruce answers as well on suitable ground, and See also:larch and other trees are sometimes substituted. The conifers are allowed to grow to a height of from 3 to 5 ft. before the young oaks are planted, and are gradually thinned out as the latter increase in size. The distance between the oaks depends upon the growth intended before thinning the young wood; usually they are placed from 8 to 12 ft. apart, and the superabundant trees cut out as they begin to interfere with each other. The See also:lower branches often require removal, to ensure the formation of a tall straight trunk, and this operation should be performed before the superfluous shoots get too large, or the timber will be injured; but, as with all trees, unnecessary pruning should be avoided, as every See also:branch removed lessens the vigour of growth. Where artificial copsewood is the See also:object, See also:hazel, See also:hornbeam and other bushes may be planted between the oaks; but, when large timber is required, the trees are best without undergrowth. The growth of the oak is slow, though it varies greatly in different trees; Loudon states that an oak, raised from the acorn in a See also:garden at See also:Sheffield Place, See also:Sussex, became in seventy years r 2 ft. in circumference; but the increase of the trunk is usually very much slower, and when grown for large timber oak can rarely be profitably felled till the first See also:century of its growth is completed. The tree will continue to form wood for 150 or 200 years before showing any symptoms of decay. As firewood oak holds a high position, though in Germany it is considered inferior to See also:beech for that purpose. It makes excellent See also:charcoal, especially for metallurgic processes; the Sussex See also:iron, formerly regarded as the best produced in Britain, was smelted with oak charcoal from the great woods of the adjacent See also:Weald, until they became so thinned that the See also:precious See also:fuel was no longer obtainable. An important product of oak woods is the bark that from a remote period has been the See also:chief tanning material of Europe. The most valuable kind is that obtained from young trees of twenty to See also:thirty years' growth, but the trunks and boughs of timber trees also furnish a large See also:supply; it is separated from the tree most easily when the sap is rising in the spring. It is then carefully dried by the free See also:action of the air, and when dry built into long narrow stacks until needed for use. The value of oak bark depends upon the amount of See also:tannin contained in it, which varies much, depending not only on the growth of the tree but on the care bestowed on the preparation of the bark itself, as it soon ferments and spoils by exposure to wet, while too much See also:sun-See also:heat is injurious. That obtained from the sessile-fruited oak is richer in tannic See also:acid than that yielded by Q. pedunculata, and the bark of trees growing in the open is more valuable than the produce of the dense forest or See also:coppice. The bark of young oak branches has been employed in See also:medicine from the days of Dioscorides, but is not used in See also:modern practice. The astringent principle is a peculiar kind of tannic acid, called by chemists quercitannic, which, yielding more See also:stable compounds with gelatine than other forms, gives oak bark its high value to the See also:tanner. According to Neubauer, the bark of young oaks contains from 7 to io% of this principle; in old trees the proportion is much less. The acorns of the oak possess a considerable economic importance as See also:food for See also:swine. In the Saxon period the " See also:mast " seems to have been regarded as the most valuable produce of an oak wood; nor was its use always confined to the support of the herds, for in time of dearth acorns were boiled and eaten by the poor as a substitute for See also:bread both in England and France, as the sweeter produce of Q. Esculus is still employed in southern Europe. Large herds of swine in all the great oak woods of Germany depend for their autumn See also:maintenance on acorns; and in the remaining royal forests of England the inhabitants of the neighbouring villages yet claim their ancient right of " See also:pannage," turning their hogs into the woods in October and November. Some trees of the sessile-fruited oak bear sweet acorns in Britain, and several varieties were valued by the ancient Italians for their edible fruit. A peculiar kind of See also:sugar called quercite exists in all acorns. A See also:bitter principle to which the name of quercin has been applied by See also:Gerber, its discoverer, has also been detected in the acorn of the See also:common oak; the nutritive portion seems chiefly a form of See also:starch. A spirit has. been distilled from acorns in process of germination, when the saccharine principle is most abundant. The British oak grows well in the northern and See also:middle states of America; and, from the superiority of the wood to that of Q. See also:elba and its more abundant See also:production of acorns, it will probably be much planted as the natural forests are destroyed. The young trees require See also:protection from storms and late frosts even more than in England; the red pine of the north-eastern states, Pinus resinosa, answers well as a See also:nurse, but the See also:pitch pine and other species may be employed. In the southern parts of See also:Australia and in New See also:Zealand.the tree seems to flourish as well as in its native See also:home. The oak in Europe is liable to injury from a great variety of See also:insect enemies: the young wood is attacked by the larvae of the small See also:stag-See also:beetle and several other See also:Coleoptera, and those of the wood-See also:leopard See also:moth, See also:goat moth and other See also:Lepidoptera feed upon it occasionally; the foliage is devoured by innumerable larvae; indeed, it has been stated that See also:half the plant-eating See also:insects of England See also:prey more or less upon the oak, and in some seasons it is difficult to find a See also:leaf perfectly free from their depredations. The young shoots are chosen by many species of Cynipidae and their See also:allies as a receptacle for their eggs, giving rise to a variety of. See also:gall-like excrescences, from which few oak trees are quite free. Of the See also:European timber trees of the genus, the next in importance to the British oak is Q. Cerris, the See also:Turkey oak of the nurserymen. This is a See also:fine species, having when young straighter branches than Q. Robur, but in old age the boughs generally See also:curve downwards, and the tree acquires a wide spreading See also:head; the bark is dark brown, becoming See also:grey and furrowed in large trees; the foliage varies much, but in the prevailing kinds the leaves are very deeply sinuated, with pointed, often irregular lobes, the footstalks short, and furnished at the base with long linear stipules that do not fall with the leaf, but remain attached to the bud till the following spring, giving a marked feature to the young shoots. The large sessile acorns are longer than those of Q. Robur, and are dark-brown when ripe; the hemispherical cups are covered with long, narrow, almost bristly scales, giving them a mossy aspect; the fruit ripens the first autumn. The foliage in some of the numerous varieties is almost evergreen, and in Britain is retained long after the autumnal withering.
This oak abounds all over the See also:Turkish peninsula, and forms a large portion of the vast forests that clothe the slopes of the See also:Taurus ranges and the south shores of the Black Sea; it is likewise common in See also:Italy and Sardinia, and occurs in the south of France and also in See also:Hungary. It was introduced into England by See also: It seems peculiarly adapted for the mild moist climate of See also:Ireland. In North America, where the species of oak are very numerous, the most important member of the See also:group is Q. elba, the white oak, abounding all over the eastern districts of the See also:continent from See also:Lake See also:Winnipeg and the St See also:Lawrence countries to the shores of the Mexican Gulf. In aspect it more nearly resembles Q. Robur than any other species, forming a thick trunk with spreading base and, when growing in glades or other open places, huge spreading boughs, less See also:twisted and gnarled than those of the English oak, and covered with a whitish bark that gives a marked character to the tree. The leaves are large, often irregular in form, usually with a few deep lobes dilated at the end; they are of a See also:bright See also:light green on the upper See also:surface, but whitish beneath; they turn to a See also:violet tint in autumn. The See also:egg-shaped acorns are placed singly or two together on short stalks; they are in most years sparingly produced, but are occasionally See also:borne in some abundance. On See also:rich loams and the alluvial soils of See also:river-valleys, when well drained, the tree attains a large size, often rivalling the giant oaks of Europe; trunks of 3 or 4 ft. in diameter are frequently found, and sometimes these dimensions are greatly exceeded. The wood is variable in quality and, though hard in texture, is less durable than the best oak of British growth; the heart-wood is of a light reddish brown varying to an See also:olive tint; a See also:Canadian specimen weighs 52k lb the cubic foot. Q. obtusiloba, the See also:post oak of the backwoodsman, a smaller tree with rough leaves and notched upper lobes, produces an abundance of acorns and See also:good timber, said to be more durable than that of the white oak. The See also:pin oak, sometimes called the " See also:burr-oak," Q. macrocarpa, is remarkable for its large acorns, the cups bordered on the edge by a fringe of long narrow scales; the leaves are very large, some-times from to in. to t ft. in length, with very deep lobes at the lower part, but dilated widely at the See also:apex, and there notched. The tree is described by Prof. C. S. See also:Sargent (See also:Silva of North America) as one of the From Michaux, op. cit. Plate See also:XXXV. FIG. 5.—Q. rubra. most valuable timber trees of North America, its wood being See also:superior in strength even to that of Q. See also:alba, with which it is commercially confounded. The over-cup oak, Q. lyrata, is a large tree, chiefly found on swampy See also:land in the southern states; the lyrate leaves are dilated at the end; the globose acorns are nearly covered by the tuberculated cups. In the woods of See also:Oregon, from the See also:Columbia river southwards, an oak is found bearing some resemblance to the British oak in foliage and in its thick trunk and widely-spreading boughs, but the bark is white as in Q. alba; it is Q. Garryana, the western oak of T. See also:Nuttall. This tree acquires large dimensions, the trunk being often from 4 to 6 ft. in diameter; the wood is 'strong, hard and close-grained; the acorns are produced in great quantity, and are used by the See also:Indians as food. The red oak, Q. rubra, has thin large leaves on long petioles, the lobes very long and acute, the points almost bristly; they are See also:pink when they first expand in spring, but become of a bright glossy green when full-grown; in autumn they change to the deep See also:purple-red which gives the tree its name. See also:Coin- , mon throughout the northern and middle states and See also:Canada, the red oak attains a large size only on good soils; the wood is of little value, being coarse and porous, but it is largely used for cask-staves; the ,l bark is a valuable tanning material. A species nearly allied is the See also:scarlet oak, Q. coccinea, often confounded with the red oak, but with larger leaves, with long lobes ending in several acute points; they change to a brilliant scarlet with the first October frosts, giving one of the most striking of the various glowing tints that render the See also:American forests so beautiful in autumn. The trunk, though often of considerable size, yields but an indifferent wood, employed for similar purposes to that of Q. rubra; the bark is one of the best tanning materials of the country. Both these oaks grow well in British plantations, where their bright autumn foliage, though seldom so decided in tint as in their native woods, gives them a certain picturesque value. Nearly akin to these are several other forms of little but botanical See also:interest ; not far removed is the black or See also:dyer's oak, From Kotschy, op. cit. Plate XL. Q. tinctoria, a large and handsome species, with a trunk sometimes 4 ft. in FIG. 6.—Q. castaneaefolia. diameter, not uncommon in most forests See also:east of the See also:Mississippi, especially in - somewhat upland districts. The leaves are frequently irregular in outline, the lobes rattle'. short and blunt, widening towards the end, but with setaceous points; the acorns are nearly globular. The wood is coarsely grained, as in all the red-oak group, but harder and more durable than that of Q. rubra, and is often employed for See also:building and for See also:flour-barrels and cask-staves. The bark, very dark externally, is an excellent tanning substance; the inner layers form the See also:quercitron of See also:commerce, used by dyers for communicating to fabrics various tints of yellow, and, with iron salts, yielding a See also:series of brown and drab hues; the colouring See also:property depends on a crystalline principle called quercitrin, of which it should contain about 8 %. The cut-leaved oaks are represented in eastern Asia by several species, of which Q. mongolica is From Kotschy, op. cit. Plate XXXVIII.
widely spread over Dahuria, north China and the adjacent countries; one of the See also:Chinese silkworms is said to feed on the leaves.
The See also:chestnut oaks of America represent a sectioh distinguished by the merely serrated leaves, with parallel See also:veins See also:running to the end of the serratures. Q. Prinus, a beautiful tree of large growth, and its subspecies castanea and See also:montana, yield good timber. Q. Chinquapin or prinoides, a See also:dwarf species, often only i ft. in height, forms dense See also:miniature thickets on the barren uplands of See also:Kansas and See also:Missouri, and affords abundant sweet acorns; the tree is called by the hunters of the plains the "-shin-oak:" Q. castaneaefolia, represented in-fig: 6,
From Michaux, Histoire See also:des
chines de 1' Amiriquo.
is a native of the woods of the Transcaucasian region of western Asia.
Evergreen oaks with entire leaves are represented in North America by Q. vtrginiana, also known as Q. virens, the live oak of the southern states; more or less abundant on the Atlantic coasts of the Carolinas and See also:Florida, its true home is the country around the Mexican Gulf, where it rarely grows more than 50 or 6o m. inland. The See also:oval leaves are dark-green above, and whitish with stellate hairs beneath, the margin entire and slightly recurved. The live oak is one of the most valuable timber trees of the genus, the wood being extremely durable, both exposed to air and under water; heavy and close-grained, it is perhaps the best of the American oaks for See also:shipbuilding, and is invaluable for water-wheels and See also: The evergreen oak of southern Europe is Q. Ilex, usually a smaller tree, frequently of rather See also:shrub-like See also:appearance, with abundant glossy dark-green leaves, generally ovate in shape and more or less prickly at the margin, but sometimes with the edges entire; the under surface is hoary; the acorns are oblong on short stalks. The ilex, also known as the " holm oak " from its resemblance to the See also:holly, abounds in all the Mediterranean countries, showing a partiality for the sea air. The See also:stem sometimes grows 8o or 90 ft. in height, and old specimens are occasionally of large diameter; but it does not often reach a great size. In its native lands it attains a vast age; See also:Pliny attributes to several trees then growing in See also:Rome a greater antiquity than the See also:city itself. The wood is very heavy and hard, weighing 70 lb the cubic foot; the colour is dark brown; it is used in See also:Spain and Italy for furniture, and in the former country for See also:fire-wood and charcoal. In Britain the evergreen oak is quite hardy in See also:ordinary winters, and is useful to the ornamental planter from its capacity for resisting the sea See also:gales; but it generally remains of small size. Q. Ballota, a closely allied species abundant in See also:Morocco, bears large edible acorns, which form an See also:article of See also:trade with Spain; an oil, resembling that of the olive, is obtained from them by expression. Q. Ilex, See also:var. Gramuntia, also furnishes a fruit which, after acquiring sweetness by keeping, is eaten by the Spaniards. In America several oaks exist with narrow lanceolate leaves, from which characteristic they are known as " See also:willow oaks." Q. Phellos, a rather large tree found on swampy land in the southern states, is the most 'important of this group ; its timber is of indifferent quality. The See also:cork oak, Q. Suber, the bark of which yields cork (q.v.), is a native of the See also:west Mediterranean See also:area. In Spain the wood is of some value, being hard and close-grained, and the inner bark is used for tanning. From its rugged silvery bark and dark-green foliage, it is a handsome tree, quite hardy in Cornwall and Devonshire, where it has grown to. a large size. The valonia of commerce, one of the richest of tanning materials, is the acorn of Q. Aegilops, a fine species indigenous to Greece and the coasts of the See also:Levant, and sometimes called the " Oak of See also:Bashan." The very large acorns are remarkable for their thick cups with long reflexed scales; the leaves are large, oblong, with deep serratures terminating in a bristle-like point. The cups are the most valuable portion of the valonia, abounding in tannic acid; immature acorns are sometimes exported under the name of " camatina." The allied Q. Vallonea of Asia See also:Minor likewise yields valonia. Some oaks are of indirect importance from products formed by their insect enemies. Of these the See also:Aleppo gall (see See also:GALLS) is yielded by Q. infectoria, a native of Asia Minor and western Asia. Q. coccifera, a small bush growing in Spain and many countries around the Mediterranean, furnishes the See also:kermes dye (KERMES). Q. persica, or according to some Q. mannifera, attacked by a kind of Coccus, yields a sweet exudation which the Kurds collect and use as See also:manna, or as a substitute for See also:honey or sugar in various confections (see MANNA). Additional information and CommentsThere are no comments yet for this article.
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