Quercus petraea

The sessile oak or durmask oak is the white oak group (Quercus) in the beech or Fagaceae family, and is native to most of Europe and into Anatolia and Iran. It is similar to the English oak (Q. robur), with which it overlaps extensively in range. It can live to be up to 1,200 years old.

Significant botanical differences from English oak (Q. robur) include the stalked leaves, and the stalkless (sessile) acorns from which one of its common names is derived. It also has branches that are more upright.

• Leaves are alternate, simple, have 10 to 18 lobes, are large, long-stalked,up to 18 cm long and 15 cm across. The leathery foliage is glossy deep green above and downy below.
• Male flowers are catkins produced in the spring; females are small in conspicuous.
• Fruit is an acorn 2–3 cm long and 1–2 cm broad, maturing in about six months.