Oak, English (Quercus robur)

The ruling majesty of the woods, the wise old English oak holds a special place in our culture, history, and hearts. It supports more life than any other native tree species in the UK; even its fallen leaves support biodiversity.

Common names:
English oak, pedunculate oak, common oak

Scientific name:
Quercus robur

Family:
Fagaceae

Origin:
Native

A large, deciduous tree growing up to 20–40m tall. Also known as common oak, this species grows and matures to form a broad and spreading crown with sturdy branches beneath.

What does English oak look like?

Leaves:
Around 10cm long with 4–5 deep lobes with smooth edges. Leaf-burst occurs mid-May and the leaves have almost no stem and grow in bunches

Flowers:
Long, yellow hanging catkins which distribute pollen into the air.

Fruits:
Acorns are 2–2.5cm long, on long stalks and in cupules (the cup-shaped base of the acorn). As it ripens, the green acorn turns brown, loosens from the cupule and falls to the canopy below, sprouting the following spring.

Where to find English oak:
English oak is a very common tree. It is especially common in deciduous woods in southern and central Britain. In fact, it’s so frequent that it has assumed the status of a national emblem.

Value to wildlife:
Oak forests support more life forms than any other native forest. They are host to hundreds of insect species, supplying many birds with an important food source. In autumn, mammals such as squirrels, badgers and deer feed on acorns.

Flower and leaf buds of English oak are the food plants of the caterpillars of purple hairstreak butterflies.

The soft leaves of English oaks break down with ease in autumn and form a rich leaf mould beneath the tree, supporting invertebrates such as the stag beetle, and fungi, like the oakbug milkcap. Holes and crevices in the tree bark are perfect nesting spots for the pied flycatcher, redstart or marsh tit.

Bats also roost in old woodpecker holes or under loose bark, as well as feeding on the rich supply of insects in the tree canopy.

Mythology and symbolism:
The oak was sacred to many gods, including Zeus, Jupiter and the Celtic Dagda. Each of these gods ruled over thunder and lightning, and oak trees are often hit by lightning as they are the tallest living feature in the landscape.

Druids practised rituals in oak groves and cherished the mistletoe that grows in oak-tree branches. It’s also linked with royalty: ancient kings and Roman Emperors wore crowns of oak leaves.

In England, the oak is a national symbol of strength. Couples were wed under ancient oaks in Oliver Cromwell’s time. Oak is the emblem of many environmental groups, including the Woodland Trust.

Uses of English oak:
Oaks produce one of the hardest and most durable timbers on the planet. However, it takes up to 150 years before an oak is ready to use in construction. It has been a prized hardwood timber for thousands of years and is still used for flooring, wine barrels and firewood.

Other uses of oak:
Tannin found in the bark has been used to tan leather since at least Roman times. Leaves, bark and acorns were believed to heal many medical ailments, including diarrhoea, inflammation and kidney stones. Acorns have also been used to make flour for bread making.