Oak

General information

The oaks have sheets laid out in a spiral way, with the edge lobed in many species; some have whole sheets with a smooth or toothed edge. The flowers are kittens which appear in spring. The Fruit is a Akène, called nipple, fixed in a structure called Cupule; each nipple contains a seed (seldom two or three) and puts to mature 6 to 18 months according to the species. For the moderated zone, it is a raised tree, rising up to 40 m height (less if it is insulated). Its trunk is right and powerful. Its summit is important. It can live up to 4000 years (known record), and easily more than 500 years, but it in Europe is generally exploited before 250 years. When the plant is young person and still relatively low, one will speak about chêneau .

A forest of oaks is a Chênaie. The oak often forms mixed forests in partnership with others Feuillu S.

They are very much used in cabinet work and Menuiserie. The tercentenary oaks of the Forêt of Tronçais (in the To combine) are classified and prohibited exploitation since 1899.

Classification

See also: List of the species of the kind Quercus

The kind is divided into several sections:

Section Quercu (synonymous Lepidobalanus and Leucobalanus ), the white oaks of Europe, of Asia and America. Short styles; nipples slightly mature in 6 months, soft or land-marks, endocarpe glabrous.

Section Mesobalanus , the oaks of Hungary and related of Europe and Asia. Long styles; nipples mature in 6 months, land-marks, endocarpe glabrous. (enough close to the section Quercus and sometimes included in this one).

Section Cerris , the oaks of Turkey and related S of Europe and Asia. Long styles; nipples mature in 18 months, very bitter, endocarpe glabrous or slightly duveteux.

Section Protobalanus , the intermediate oaks between the red oaks and oaks white, originating in the South-east of the United States and the North-West in Mexico. Short styles, the nipples mature in 18 months, very bitter, duveteux endocarpe. All the species of this group are sempervirentes, with a persistence of the sheets higher than 1 year, and often 3 years.

Section Lobatae (synonymous Erythrobalanus ), the red oaks or blacks of North America and Central America and Colombia. Long style, long nipples mature in 18 months, very bitter, duveteux endocarpes.

The hybrids are current only between species within the same section; no hybridization checked between species of various sections is known, except for those between species of the section Quercus and Mesobalanus , where several take place.

The kind Cyclobalanopsis , regarded here as a distinct kind, according to Flora off Clouded , is often included in other classifications in the Quercus kind like a sub-genus.

Use

The oaks are trees with hard Bois. The wood of oak has a density of approximately 0,75 g/cm ³. It is a very resistant and very hard material. Its resistance to the insects and the mushrooms (natural durability) is very important thanks to its strong content of tannin. The large radial boards of oak are appraisals since the Middle Ages and are used to carry out woodworks of interior of prestigious building like the House of Commons in England in London, and in the construction of fine joinery. The wood of oak, the oak stalk and the oak reopens was used in Europe for naval construction to the 19th century and the principal wood turpentines used in the construction of the wooden carpentries of the buildings in Europe. Today the wood of oak remains usually used in joinery, the making of floors, and the production of plating. The barrels in which the red wines, Jerez and other spirits such as the Scotch tape whiskey and the bourbon are out-of-date, are barrels of oaks. The barrels of oak contribute to savors vanilla of these drinks. The shavings of oaks are used for the manuring of fish, the meat, cheese and other food products.

Among the North-American oaks, the red oak of America Quercus will rubra is snuffed the most for its wood within the group Lobatae . All the species of this group are marketed as a " oak rouge". The standard wood of the oaks of the group Quercus , which all are marketed as a " oak blanc" , Quercus alba is the white oak. The wood of the oak stalk Quercus robur and of the sessile oak Quercus petraea , both with null and void sheets, represents most of the production of oak in Europe, but persistent species, such as the Holm oak Quercus ilex , and the Chêne-liège Quercus suber produce also a wood of value.

Quercus will coccifera is parasitized by the Kermès, or cochineal, a Insecte whose dried egg S and treaties were used to make a dyeing of scarlet color;
Quercus pubescens is as for him the best truffle oak, the alive Mycélium of the Truffe in partnership with its root S;

Uses of the bark

The bark of Quercus suber , or cork oak, gives the cork which is traditionally used to manufacture the cork stoppers. This species pushes on the Mediterranean circumference, like in Portugal. Spain, Algeria and Morocco are the largest world producers. The bark of oak pulverized gives the tan, used for the preparation of the Cuir S. the bark of the white oak is dried and used in certain medical preparations. The bark of oak is rich in tannin, and is used by the tanners for the tanning of leather.

Uses of the fruits

The nipples can be consumed by the human ones (see Purée of nipples). The nipples are used for to make a flour or roasted like substitute of coffee beans. the nipples are also eaten by the wild animals or servants: the squirrels, stags, the wild boars which are very fond of delicacies.

The nipples are used in Spain for the food of the pigs which will use to make ham of Jabugo or ham of bellota.

Uses of Wales

One calls nut gall (or Galle of the oak ) the outgrowth caused on the sheets of certain oaks by punctures of another Insecte, the Cynips - the nut gall is used for the clothes industry of dyeings;

Wales of oaks a long time were used as principal ingredient for fabiquer ink, collected at one precise period of the year.

Ravageurs and diseases

The Sudden death of the oak ( Phytophthora ramorum ) is caused by a Oomycète which can cause the death of the oaks in a few weeks. The fading of the oak, caused by a mushroom Ceratocystis fagacearum (a mushroom very close to the Graphiose of the elm), it is also a lethal disease of certain oaks, particularly the red oaks (the white oaks can be infected but they survive generally longer). Among the other risks, one finds the digger insects borers and insects whose presence could not be obvious in the case of the oldest trees and are often only discovered when the trees fall at the time of strong gusts. The apples of oak are of Wales which develop on the oaks and are caused by a gallicole species of hyménoptère (family of the wasps in Wales). The female of the Cochenille S of the kind Kermes is responsible for the formation of Wales on the Kermes oak. The oaks are used as feeder plants for the Larve S of many species of Lépidoptère S.

to also see Listes of the lépidoptères nourishing oaks

Description

The edge of the Feuille S lobed, is cogged or whole. The sheets are simple and alternate. The Fruit is a Akène, called nipple, fixed in its Cupule - the nipple of the oak stalk has a length Pédoncule whereas the nipple of the sessile oak has a stalk runs.

One distinguishes two main categories of oaks: those whose foliage is null and void, falling in autumn, sometimes with the Printemps (oaks red, hairy Chêne, pubescent Chêne, Chêne tauzin and Chêne reopens); those whose sheets are persistent, trees pushing especially on the Mediterranean shores (Holm oak, Kermes oak and Chêne-liège) like in subtropical and tropical zones in America and Asia. The first, generally larger, have sheets divided into lobes or crénelées ; the seconds have whole sheets or with thorny teeth. The tropical species have whole sheets, comparable with the form of certain Lauraceous (camphor tree, etc…). the edge of the sheet is not cogged. The veins are very visible.

History of the oak in Europe

Antoine Kremer (research director, Inra) showed by the study of genes of oaks and the study of fossil pollens that at the time of the Glaciation S the preceding ones of the populations of oaks survived in certain zone-refuges ajourd' today located in Spain, Italy and in Balkans before reconstituting the current populations of Europe. One now seeks to include/understand how the insects and the mushrooms associated with the oaks influenced their biodiversity and their adaptivity in the mediums that they (Re) colonized. This research should help to pre-empt the answers of the trees and forests with the climate changes.

Thirty to forty percent of the sessile oaks and European stalks push today in France, which makes of it the second world producer, after the the United States, and in front of the Ukraine who could soon dominate the die wood of oak because according to the forecasting models of climate (INRA), the oak, as the beech could be threatened in France in the decades and centuries to come. In 2004, the oak grove (stalk and sessile, often mixed with other gasolines) there covered in 2005 approximately 5,1 million hectares, for an estimated volume of 750 million cubic meters of wood, with a harvest which was in 2004, of 2,6 million cubic meters (90% of sawing, 8% of Merrain, 2% of cutting, the cutting being in regular reduction since 20 years). In 2004, France also exported a few 130.000 m ³ of barks and 150.000 m ³ of oak of trituration. (all into important 93.000 m ³ of barks in 2005). 850.000 m ³ were sawn, but sawing is in retreat since the years 1970.

List species

The kind Quercus account 465 species. They are mainly present in the areas moderated at subtropical of the northern hemisphere, with an incursion in Indonesia, but also in the tropical forests of altitude.

List of the species and subspecies (noncomplete and excluding the horticultural varieties)

The Densité of the Bois of oak lies between 0,61 and 0,98 (heart: 1,17). It is a heavy, hard and resistant wood.

Names of the oak

The Indo-European word *doru “tree” is found in the Breton derw , “oak”. The Slavic languages know forms like the Russian , the Czech dub and the Polish dąb .

There is no word indoeuropéen specific to the oak, a tree which draws its names in older linguistic layers. In spite of charming the popular etymology by Breton the kàer gwez (Celtique *kadro *uidhu ) “beautiful tree”, Latin quercus , comes from an old root *kwar-k- (cf Finnois will vaara “hill wooded”). This word, which one will specify that it was female like all the names of Latin trees, survives in Italian quercia and in Corsica querciu .

The root *karr is at the origin of words Latin cerrus , Iberian arte , karraska , carballo, Occitan garric , garrolha , the Limousin jarri , Berbère akarruš , Slovenien hrast .

The root *aik , *aig explains the terms German Eiche , English oak and the words Greek S aigilops , krataigos .

The the Holm oak, most widespread as Mediterranean countries, is called in Catalan alzina , Occitan auzina , Spanish encina , of a derivative *ilicina of Latin ilex . This last gives the French terms yeuse , Italian leccio , Corsica leccia .

The word “oak” (initially chasne in Former French) is attested in Latin medieval in the form casnus (886), corresponding to older cassanus (derivative preceltic of *karr ). In other words, this term was not supplanted by Latin quercus , undoubtedly because of importance which this tree for constructions had. The regional forms are distinguished: surface Picardy E: quesne , west and north-occitan: chasne , north-eastern quarter chesne , oak , south-west cassou, breakage (the cassagne). In Gascogne, this name applies to the large oaks with null and void sheets which one distinguishes from the Tauzin ( Quercus pyrenaica ), exactly as the Basque S distinguish l' haritz stalk from l' ametz (tauzin) and from l' arte (yeuse). The Breton S, them, distinguish the tan (reopens), of the taouz (tauzin).

Latin robur (allotted in taxonomy to the Oak stalk), gives in French Rouvre (rivoire) and explains the terms Catalan roure and Spanish roble (generic names of the oaks with null and void sheets).

The cork oaks were called in Latin suber , to bring closer to the Basque zuhar “Orme”, of zu (R) - “wood”. One finds it in the terms Corsican will suvera , Catalan alzina will surera , Portuguese sobreiro and French Sûrier .

Remarkable trees

The ancient oak of France would date from the time of Charlemagne. It is located at Allouville-Bellefosse (Seine-Maritime). In Belgium, the ancient oak is located at Liernu. the ancient oak of Europe east in Switzerland, in the Jura with Chatillon.

Certain oaks stalks have a fastigié port, opening gradually with the age (pyramidal oaks).

Certain varieties, like the Oak stalk, can live 1.100 years!

In Cheillé, close to Azay-the-Curtain, (Indre-et-Loire), a oak several times centenary, pushes in the wall of the Saint-Didier church. The trunk and the roots of this beautiful oak stalk are inserted inside the wall.

Symbols

Of many trees of this species is in charge in the popular tradition (considering the reputation of hardness of wood) of a great value symbolic system in Europe, often related to a context of justice:

- In France, the king Saint Louis returned justice under a majestic oak.

- In Great Britain, Robin of Wood had his general headquarter in a oak of the Forêt of Sherwood.

the oak symbolizes in several European cultures perenniality. The weddings of oak are celebrated after 80 years of marriage in the French folklore.
Tree crowned at the Roman , the Celtic and the German , the oak symbolizes the Virilité, the force, the Endurance and the Longévité.
Several Pays makes use of the branch of oak like symbol of the stability of their political regime:

- in Germany: the pfennigs and centimes of Euro S of this country are illustrated by a branch of oak.

- in France: the Monnaie S in frankly often carried a crown of olive-tree and oak.

the sheet of oak also decorates in France the Képi of the general officers and certain decorations such as the Légion of honor and the medal of the National order of the Merit.
Charles de Gaulle was represented, the shortly after its death, in the shape of a shot down oak, in a drawing of Jacques Faizant with the one of the Figaro ,

Medical virtues

The bark, the Nipples and the Sheets, rich in Tannins, have a capacity very powerful Astringent.

References

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