OAK (AS. fie, 011G. rill, Oer. ,Eiehr, oak; connected with Lat. (rseulus, Gk. ai-yii<01,, aigi lops, oak). Quereus. A genus of trees and shrubs of the natural order Cupnliferce, having a three celled ovary, and a round (not angular) nut (acorn) placed in the lower part of and invested by a scaly truncated cup. The species number about 300 and are natives of temperate and tropical countries. Several are found in Europe. North America produces many, and many are natives of Asia, especially of mountainous re gions. None are found in tropical Africa, in Australia, or in South America except in the most northern parts. The oaks have alternate simple leaves, which are entire in some, but in the greater number variously lobed and sinuated or cut ; evergreen in some, hut more generally decidu ous, when they have well-developed winter buds.
The oaks are famous for the strength and dura bility of their timber, the majesty of their ap pearance, and their great longevity. They reach maturity in from 120 to 200 years, depending upon the species, and well-attested specimens nre known to he nearly 1000 years old. Some species rise tall and stately to a height of from 50 to 100 or even 150 feet, and have thick trunks and wide-spreading branches. The trunk is often four, six. or even eight feet in diameter. The hak succeeds best ill loamy soils, and especially in those that are somewhat caleareons. The lim ber is very solid. durable, peculiarly insuseepti ble of the influence of moisture, and therefore eminently adapted to It is also employed in carpentry. mill work. etc. The bark abounds ill tannin. and contain, a peculiar hitter principle called quereine.and is used in medieine, chiefly in gargles, on account of its astringency. sometimes also as a tonic: it is used along with in the manufacture of ink: but most of all for tanning (see BARK), on which account the oak is often planted as (see COPSE) in situations \Olen` it cannot e he expected to attain great size as a tree. The acorns of some trees cork of commerce is obtained, is a native of Spain and the north of Africa. (See ConK.) The Valonia oak -Egilops). of Eastern Europe and Asia and extensively planted in Algeria and elsewhere. is celebrated for the amount of tannin contained in its acorns and cups. large quantities of Which are used in tan ning leather. The gall oak (Qacrcus lusita ica). a common. low shrub native of Asia Alinor, is noted for the galls produced upon its leaves hy insects.
ln the United States more than 50 species of oaks are found with a score or inure additional described varieties :11m1 hybrid.,. Some species are very restricted ill their distribution, being known from a single locality, where others range froni il?faine to and southward to the Gulf of Mexico. The American species. and are also much less bitter than others, and species occur which produce acorns as sweet as CheStIllItA.
Et0110111iCally the principal oak of Europe, also distributed Over .Isis, is Qui reus robur, the British oak, of wide!' there are two well-known varieties, and ssili/11.01, 5,) named because in the former the acorns have stalks, in the latter not. These and other differences in habit have no apparent influence 1111(111 the value of the timber. these varieties. which some 1)0i a Ill ist .• call distinct spe cies, is more abundant ill the north and .s.cs.,ifijbirti, often called durmast oak, in I he south. The Turkey, or Adriatic oak. some
.1u-trian oak (Qmrctis Cerrisl, na tive to Siiiithemdern Europe, is large and valnahle and eNteti,i‘.•ly planted. Its leaves are acutely lobed :Ind the cops of the acorns illIVe long acute bracts, from which it is called tleny.co1ped. The 'holm or evergreen oak ( OriercuR 3-1 is an eVergrecil (-specie, ()Cell lig commonly in south of l'irope. 11 is more fully de srribrd model Ex. Tile cork oak tirgr(l 1/(b)-Rlde'r ), from the bark of which the possibly the others, readily fall into two great groups. t lie white oaks and black oaks, spectively, the former with never bristle-tipped leaves, and acorns which ripen the first year; the latter with acute tipped leaf haws. and fruits which mature the seeond year. The American white oak (Querrns allm 1, a large tree of rather rapid growth and (nigh. hard. strong. plo,e-grained wood, is one of the most valuable of timber trees. It is found from to the gulf and west to Texas. The bur Or mossy-cup oak (Q !wrens snarro rwrinI), is a large tree of iniu.11 the appearance and distribution of the white oak and is one of the most valuable for NVestern planting. Its timber is eoarser grained and not :-.1) titr011g, but 1/therWke equals that of the former The red Oak (Quercits ruhr(t) and the scarlet oak IQ If corvinea) are large, valuable trees that occupy about the same territory. They belong to the seeond class of elks 1W111101111 alcove. Their timber is (•oarse-grained, heavy, bard, and strong, and is used ill various of building 1111d for furniture. No dilrerence between the two is noticed in the lumber trade. The chest nut oak (Qucrc•us Prinus) is a large tree with a deeply furrowed bark and leaves resembling those of the chestnut. The bark, which is rich in tannin. is used extensively in tanning leather. The chinquapin oak Ulu( rcus acuminala), and the dwarf chinquapin oak prirmidcs), by some botanists referred to ()nen-us /'rims, bear edible acorns. The yellow 110 k, or quer citron ((luercus tinriori(r), or Quercas disco/or of some 144:mists, yields a valuable bark for use in tanning, and a dyestuff, quereitron. The live oak (l,e((lrc•us rircns or Qucrells is found growing in the rich soil of moist cli mates from Virginia to Texas, also in California, Mexico, Central America, and Cuba. It is one of the hardiest of the evergreen oaks, attaining a height of 00 feet or more, and six to eight feet in diameter. It was formerly extensively used in ship-building. The Spanish oak of the southeast ern United States is variously called 0/wrens dillitaht and QIWITUR dilututa, the latter name being also applied to an East Indian species.
The name oak is given to many other trees and plants not related to Que•cus. The African oak is a kind of teak (q.v.). In Australia a 1111n1110• of species of Casuarina (q.v.) are called oak, as are also species of Grevillea, Lagunaria, etc. Elms toxieodendron is often called poison oak in the 'United States, etc. Fossil oak leaves are known in the Cretaceous rocks, where are also found some forms intermediate between the oaks and chestnuts. These latter indicate for the two genera Quercus and Castanea a common ancestry ill early Cretaceous times. In the Ter tiary oaks were members of the vege tation and ranged to far northern latitudes, for their leaves are found in the bove• Eocene beds of Disco Island, on the west coast of Greenland.