The common oak is one of the most important and most widely distributed of European broad-leaved trees. Its range extends from Spain eastwards as far as the Ukraine and northwards as far as Sweden. It grows to an age of 600 to 800 years and, in the open, develops a huge trunk and broad crown. Under ideal conditions, heights of 40 metres can be attained. Up to about 20 to 30 years of age the bark is smooth and grey, in older trees it tends to become blackish-grey and deeply furrowed. The leaves are alternate with a lobed margin. The male flowers are in yellowish, slender, pendent catkins about 3 to 8 (10) centimetres long, the tiny globular female flowers are grouped in clusters of two to three on erect stalks one to three centimetres long; they appear at the beginning of May. The fruit, or acorn, is a brown elliptical nut sometimes with darker longitudinal stripes, borne in a cup on a long stalk.

The common oak grows mainly in moist bottomlands; it is the principal tree of lowland forests, where it occurs together with the elm, ash, hornbeam and lime. It grows at elevations up to 500 metres, provided that there is adequate moisture. It has a vast and deep root system and produces vigorous stump suckers when felled. The heavy, hard wood is used to make furniture, parquet flooring, barrels, boats, and other articles.