Oak (Quercus, fr. Chene blanc, Ger. Stieleiche, it. Quercia commune) – a type of trees, less frequently high shrubs, included in the beech family (Fagaceae Dumort.). It includes about 200 species occurring almost exclusively in the temperate zone of the northern hemisphere and in the higher parts of the mountains of the tropical zone. They are the southernmost in the Sunda Islands. The typical species is Quercus robur L. The oak in Poland usually reaches a height of up to 50 m and a diameter of up to 2 m. It ends the growth cycle at the age of 120-200, reaches the ripening stage at the age of 120, lives on average 600-1000 years.

PHARMACOLOGY
Oak bark has anti-inflammatory, antibacterial, astringent and disinfecting properties. It is used on the affected skin, but also in the case of problems with the digestive system. It helps primarily in inflammatory conditions of the skin and mucous membranes (eg oral cavity inflammation, pharyngitis), in case of minor damage, frostbite or lighter burns.

Decoction of oak bark is also used externally to treat haemorrhoids, i.e. varicose veins, located near the anus. The best results are obtained by taking a few-minute (10-15 min.) Sit-ups with a freshly prepared infusion of body temperature, which is approximately 36.6-37 degrees C. The same pannier can be made in the case of inflammation of the external genital organs.

Oak bark extract can also be used internally, especially in the case of ailments with the digestive system. It is recommended in the case of gastritis and bowel diarrhea, because the components contained in the bark of the oak normalize the functioning of the mucosa of the gastrointestinal tract.

CHEMISTRY
The bark of the oak contains tannins (tannins), flavonoids, resins, mineral salts, and polyphenolic compounds.

MORPHOLOGY
Buds
Multi-lobed, clustered several at the end of the branch.
Leaves
Stacked in a winding way, in some species not falling for the winter (they stay on the plant dried up), while some are almost evergreen (cork oak, holm oak). Whole-pervade (Quercus imbricaria), serrated or serrate (Quercus acutissima, Q. libani, Q. prinus), through rooted and lobed (pedunculate oak, red oak), to pinnate (“pedicular oak” ‘Pectinata’).
Flowers
Separid sexes, but the plants themselves are monoecious, airy. Male flowers collected in female cats, while female ones are single. In temperate climate species, male flowers hang loosely between the parted buds of last year’s buds, while the female flowers are straight and in the corners of the upper leaves of developing shoots.
Fruits
Nuts called acorns set individually in bowls, densely covered with small scales. They reach maturity in the first or second year.

OCCURRENCE
It includes about 200 species occurring almost exclusively in the temperate zone of the northern hemisphere and in the higher parts of the mountains of the tropical zone. They are the southernmost in the Sunda Islands.

BOTANY
English oak grows best on moist and fertile soils. There are many species of this tree in Europe.
A kind of family from the row of beechwood, belonging to the pink clad within the angiosperms. Within the family included in the subfamily Quercoideae Õrsted, in which the closest one is related to the genus Castanea and Castanopsis