The name of oak tree can be used to refer to hundreds of tree species that are specific to the northern hemisphere, being more widely spread in North America and Europe. In the 19th century the oak tree had the same role as steel has in our days. The oak tree leaves have a lobed margin and they are arranged like a spiral; the oak tree blooms in spring and the fruit, called acorns, are very similar to nuts.
The oak wood is one of the best when used in house building or furniture, it has a density of 0,75 g/cm³, and it contains a high concentration of tannin which make it resistant to insect and fungal attacks. Oak tree varieties have been very appreciated even from the Middle Ages when this type of wood was used for panel decorations in the interior of the most important state buildings.
For example the British House of Commons was constructed based on high quality oak wood. Until the 19th century oak was the raw material for ship building, but presently it is only used in the furniture and construction industries. The massive exploitation of oak forests ended with the disappearing of very old woodlands, so that at present only 5 to 10 per cent of the old forests are left.
The wine and whiskey industries still rely on oak barrels for liquor aging. Oak barrels influence the taste and color of the contents, thus contributing to the value and the prestige of the beverage. Wine producers always have a dilemma when choosing the type of oak tree to produce the barrels. The French oak makes the wine pricier while the American one can resist better to aging. Oak tree wood is also used for creating chips for smoking meat, cheese, fish or any other kind of food.
Remember that oak leaves have an increased level of toxicity, so is not a good idea to feed your horse or any other domestic animal on them; the oak tree tannin usually causes kidney or gastrointestinal problems to animals which eat them. Horses are predisposed to intoxications with oak leaves as many of them like both leaves and acorns.
The oak tree is an important cultural symbol too, since it stands for the strength and endurance through the harsh times of history, and many countries use it as a stylized representation on their national flags or heralds, thus it is present in the history of the United States, Canada, Wales, Poland, Estonia, France, Germany and many others.