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Sessile oak - quercus petraea

OAK. SEVERN WYE AND AVON.The Oak is the largest of our native broad-leaved trees.  Regarded as “kings of the forest”, Oaks are sturdy, tall with  domed crowns.  The broad rounded canopy has wide spreading thick lower branches.  There are two native Oaks in Britain and the other is the Pedunculate oak ( Quercus robur).  Both have the very special characteristics of the leaves and acorns, although there are slight differences.

Age and size

Can grow over 40 m high,  over 3m in diameter and often reach an age of 300  years old.

Bark  The Greyish bark has vertical cracks forming shapes called “plates”

Flowers and seed
The acorn is the ripened fruit or seed of the flower. It looks like an egg in a cup. On the Pedunculate Oak the flowers and acorn are on  a stalk called a “peduncle”.


oak leavesLeaves
The wavy dark green lobed leaves are very distinctive.


Where and how does the Oak grow?
The Oak likes clay soils or sandy loam soils with plenty of humus.  Sessile Oak is naturally more typical in the north and west,  Pedunculate Oak on the clay soils further south and east.   There has been so much large scale planting of both types that it is now hard to find these distinctions.  The Oak is not always huge and tall like the great Oaks in the New Forest or on many private estates.  In some conditions it can be stunted and grow into unusual, twisted forms.  Many of the remaining Oaks of the old Sherwood Forest are like this.

Wildlife and the Oak

The Oak is a habitat and community on its own and provides for an enormous variety of plants, insects, birds, reptiles and mammals - and that is just above ground!  It is late coming into leaf giving an open canopy that lets a lot of light through. This allows the ground flora to flourish.  A whole range of grasses, flowering plants and mosses are able to grow and in turn become food for a variety of insects, birds and other animals.

In upland Oak woods you may find the Killarney fern, Wilson’s pouchwort, the Chequered skipper butterfly, the Blue ground beetle or a weevil called Procus granulicollis  In a lowland mixed broad-leaved woodland you may even spot a Dormouse.


The timber from Oak has great importance in terms of wood production in this country.  The wood called brown, pollard or burr is brown in colour,  strong and hard, extremely durable and is very easy to work with when green.  It is an excellent wood to use for contact with the ground as it is very resistant.

Now used in boat and ship building, cabinet and furniture making, joinery and carving and as veneer and plywood.  The building of traditional Oak framed buildings is also becoming popular again.  The new Globe Theatre, London is made from Oak from the Forest of Dean and built in the tradition of that time. Oak sawdust is still used for smoking food to give flavour.

Old uses - The tanning industry was once the biggest user of oak wood. Also traditionally used for fencing, firewood, making charcoal and fuel for iron smelting. Some of the oldest timber framed buildings were made from Oak such as the original Shakespeare Globe Theatre.  The Lords of the Isles in Scotland had a whole war fleet of Oak warships.

It takes a long time for an Oak to grow big enough to use the wood - sometimes as long as 150 years. In some places, Oak was commonly grown as “coppice” which means the trunk and branches were cut and new branches could grow again and then again.  This gave smaller diameter wood which could be used after  a few years, especially for fuel and making charcoal in the past.  This type of woodland management is growing popular again, mainly because it greatly benefits wildlife.



What's of interest

sessile oak
British people have always loved the Oak. Its’ great size, low branches and hollows in the trunk mean it was used as a natural tree house, hiding place and social centre. Robin Hood was said to have lived in the Major Oak in Sherwood Forest. Kings and Queens have hosted many a social event around a big old Oak. Oak trees were often landmarks and are still found in many place names such as Sevenoaks in Kent, England. The Gaelic word for Oak is “dairoch” and is seen place names in Scotland such as “Craigendairoch” or “Clasindairoch”. The Welsh word “der” can be seen in place names like Derwen and Deri. In Irish “doire” means oakwood.

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