Oaks

Click here to choose Pedunculate Oak (Quercus robur)

Click here to choose Sessile Oak (Quercus petraea)

Click here to choose Turkey Oak (Quercus cerris)

 

 
Pedunculate Oak
(Quercus robur)
Simple
Lobed
Alternate

leaves

Winter twig
Winter twig

male catkins
male catkins

fruits

tree

distribution map

The alternate leaves are 5-12 cm long and have 3-5 various sized lobes on each side. They have 'ears' at the base and only a few hairs beneath, when young. The leaf stalk is very short or absent.

ID check

Pedunculate Oak is a deciduous tree, with a broad, rounded outline up to 30 m or more tall, with a bark which becomes deeply fissured with age. It is one of the commonest native woodland trees and grows on neutral or lime-rich heavy clays and loams.

Green male and female flowers are in separate clusters on the same tree (monoecious) and appear with the young leaves in May. Male flowers are in whorls of stamens in drooping catkins 2-4 cm long. The female flowers are scattered on 1-5 flowered stalks. Greenish striped, fawn acorns, ripe in October, are on long stalks, 2-8 cm long.

Facts

  • Pedunculate Oak and the closely related Sessile Oak, are the most important native trees for sustaining wildlife, especially insects, in Britain.

  • The Latin name 'robur' means sturdy, which describes the tree and its timber which are so strong and durable.

  • Acorns were once used for feeding pigs. The right to graze them in woodland was called 'pannage'


 
Sessile Oak
(Quercus petraea)
Simple
Lobed
Alternate

leaves

leaves

Winter twig
Winter twig

tree

distribution map

The alternate leaves, 5-12 cm long, have 5-6 various sized lobes on either side, and no ears at the base which narrows gradually into a leaf stalk 10-25 mm long. The leaves have persistent hairs at the base of the mid-rib beneath.

ID check

Sessile Oak is a deciduous tree with a narrower crown and more upright branching than Pedunculate Oak. However, it is also up to 30 m high: the bark too is deeply fissured with age. It is native in woodlands especially on acid soils, in the west of Britain and in Ireland.

The green male and female flowers in separate clusters on the same tree (monoecious), appear with young leaves May.

The male flowers with stamens in whorls form drooping catkins 2-4 cm long. The female flowers are clustered close together on short stalks.

The dark brown acorns, ripe in October, are clustered together on short stalks less than 
10 mm long, and are rounder than those of Pedunculate Oak.

Facts

  • Sessile Oak was much used to make charcoal for smelting iron in N and NW Britain.

  • 'Sessile' means unstalked and refers to the clustered acorns.

  • Oak bark contains tannin, which was needed in the past for making leather from hides


 
Turkey Oak
(Quercus cerris)
Simple
Lobed
Alternate

leaves

Winter twig
Winter twig

flowers

tree

distribution map

The alternate leaves are 5-10 cm long, with 7-8 various sizes of pointed lobes on each side. The leaves are paler below and hairy on both surfaces when they are young. They have no 'ears' at the base and narrow to a leaf stalk 10-25 mm long, at the base of which are pale, narrow stipules.

ID Check

Turkey Oak is a deciduous tree with a broad, rounded outline, up to 35 m tall with a bark more fissured and rough than native oaks. It was introduced as an ornamental tree but now regenerates from acorns, particularly on lime-rich soils.

Green male and female flowers are in separate clusters on the same tree (monoecious) and appear with young leaves in May.

Male flowers are in dense bunches on drooping catkins 5-8 cm long. The female clusters are inconspicuous, with 1-5 flowers.

The acorns develop in cups which are covered in long 'mossy' scales up to 10 mm long. They ripen in their 2nd year.

Facts

  • Turkey Oak was introduced to Britain from Turkey in the second half of the 19th century. It is a native of South and South-central Europe and South-west Asia.

  • The leaves hang on well into the winter and some stay until the following spring.

  • The timber is of little value as it warps and splits during seasoning

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