Cork oak (Quercus suber)
Appearance: Deciduous evergreen tree with relatively low, very wide and spreading, but the usual spherical vaulted crown, on relatively short, often slightly tilted, oblique trunk. Height up to approx 20 meters, usually only 6-10 meters. Branches short, strikingly thick, often twisted and arcuate, or vigorously branched.
Bark on younger branches and smaller trees with delicately grooved cork slats. Older trees with cork, thick, white-gray, slightly spongy bark and a pattern of widely spaced cork slats. Thick cork layers can be peeled off every seven years (cork sourcing). After debarking, the trunk gradually turns red-brown or orange-brown, until new layers of cork are recreated after some time. Only the main trunk is usually stripped of its bark, less often the lower, thicker branches. Gray-green shoots, densely and felt-hairy. Donuts, strikingly small, have only about 2 mm in length.
Leaves long 4-7 cm and width more or less 3 cm are oval or oblong, sharp at the front, plytkowrębne, on each side of z 5-6 thorns. Smooth and dark green on the outside, from underneath – greenish-gray hairy, all in all very stiff, leathery and hard, often quite clearly wavy at the edges.
Oval acorns, about 3 cm in length, deeper than half stuck in the cup. The outside of the cup is covered with large scales elongated in the upper part.
Habitat: Cork oak prefers warm, luminous, open places,
Occurrence; Quite common, especially in the western part of the Mediterranean, where it is intensively used for the extraction of cork, Cork oak forests are constantly slightly overexposed and left in a semi-natural state. This tree is characteristic of large areas in southern Spain and Portugal, but they are also common in Italy and in places in the former Yugoslavia.
Flowering period; June,
General thoughts: Match, which made cork oak the most economically important species of oak in the Mediterranean area, me is a unique creation specific to this species, but it is found in many other deciduous trees, fulfilling the same function. However, the deposited layer of cork is incomparably thicker in this species than in others. Anatomically, a kitten is a covering tissue, which is deposited by a special creative tissue outside the actual pulp. While the pulp provides the growth of new wood and gulp tissue, the creative tissue of the cork causes the development of the enveloping tissue, which provides additional protection against water loss and temperature changes. In the tree, it belongs to the zone of the proper cortex, The functional cells of the cork tissue are dead, waterless and filled with air. Thanks a lot, a wax-like substance (suberin) the cork cell walls are impregnated like this, that water cannot penetrate and the tissue is never wetted. The cork must therefore never be fully saturated with water.
The debarking work is undertaken in the summer. The first barking is performed on trees that are approximately 20 years old, but the first cork obtained is still quite brittle and is only used in tanning. Only after that is the desired smooth one formed, flexible stopper, well workable. Depending on the conditions of the habitat, it passes 6-12 lat. before a 3 cm layer of cork is formed,