Seasonal Wild Flowers

Latin name

Quercus robur

Other names

Common Oak, English Oak

Family

Fagaceae

Flowering season

May to June

English distribution

It is found throughout the country.

See the BSBI distribution map for Pedunculate Oak

Habitat

It grows in woodland and hedgerows and as isolated trees.

It has been extensively planted as a timber tree for

hundreds of years.

Description

Pedunculate Oak is a native, deciduous tree with a broad

crown and growing up to 40m.

The male flowers are in yellow-green catkins, which are

up to 8cm

long and appear at the same time as the leaves.

Each male flower has between 4 and 7 perianth lobes

and between 4 and 12 (usually 6) stamens.

Large amounts of pollen are produced for wind pollination.

Female flowers are very small and inconspicuous.

They form on separate stalks (peduncles) at the end of

the twig and at the junction of the leaves.

Initially, they are a sticky-looking, bright, glistening red

and comprise a short, thick style with 3 fleshy stigmas.

The stigmas later darken to a deep red.

The peduncle elongates up to 8cm and the individual,

sessile flowers become spaced out along the stalk.

The fruit is a one-seeded acorn.

The leaves are initially yellow-green and become a darker

green through to autumn.

They are up to 12cm long and have up to 6 pairs of

unequal, rounded lobes, with the lower 2 reflexed to form

auricles.

The petiole is either a few mm or absent.

In the autumn the leaves turn brown and drop.

Twigs are greyish-brown.

The trunks of aged trees can be several metres in

circumference and become deeply fissured and gnarled.

Pedunculate Oak is an important timber tree.

It is susceptible to a variety of insects resulting in galls.

It has a similar distribution to Sessile Oak.

Together they are the most common oaks in the UK.