The Sessile oak is native to the UK and is the national tree of Ireland. It is mainly found in the north and west of the UK, particularly in the uplands. The other native oak of the UK is the English oak which is more widespread in the south of the UK. Where the ranges overlap they will often mix and create a natural hybrid called the Devony oak (Quercus x rosacea).
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It is a large deciduous tree capable of growing up to 40m tall and can live for 500 to 1000 years. The Sessile oak is a slow-growing tree, however it does have a faster growth rate than the English oak.  It requires less light and is more drought tolerant than the English oak. As a hill-bound species, it can be found up to altitudes of 1600m.
ENTIRE TREE
BARK & TRUNK
The Sessile oak is also known as the Welsh oak, Cornish oak, Irish oak or durmast oak. It is a very important species and over 300 species of mixed wildlife rely on it for food and shelter.
CANOPY
CROWN
The buds are rounded and orange / brown in colour and clustered on the twigs. Each bud has more than three overlapping, waxy scales that protect it during the winter time. The buds of the English oak are not as prominent ​which helps with ID.
BRANCHES & TWIGS
LEAVES
The leaves of Sessile oak are dark green, lobed, and have long yellow leaf stalks. They are less deeply lobed than the leaves of the English oak.  The leaves are around 7 to 14 centimetres in length and and 4 to 8 cm in width. 
FLOWERS
FRUIT
Like most oak trees the Sessile oak is monoecious which means that both the male and female flowers are on the same tree but different parts. The male flowers are very showy catkins. which appear in April time. They are yellow / green in colour and dangle freely on the wind. The red female flowers are inconspicuous, and small in comparison and easily overlooked. They are pollinated by the wind and on a mature tree there will be tens of thousands of flowers.
BUDS
GROUND LITTER
The fruit is the iconic acorn. The growth habit of the Sessile oak acorns is different than the English oak as the acorns are borne directly on the twigs. The acorns of the English oak are on short stalks and this really helps with ID. The acorns start off bright green and as they mature they turn brown in colour. Many animals rely on acorns and in some cases they help to spread them with their burrowing habits. Squirrels and Jays are often seen in the early Autumn collecting and hiding acorns.
OTHER USEFUL DATA
Picture
The Biodiversity Heritage Library
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Carbon performance certificate by Treeconomics for Barcham Pro Trees
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Carbon capture data by Treeconomics for Barcham Pro Trees
OTHER USEFUL RESOURCES
QUICK FACTS
  • The Sessile oak is native to the UK and is the national tree of Ireland.
  • It is mainly found in the north and west of the UK, particularly in the uplands.
  • The other native oak of the UK is the English oak which is more widespread in the south of the UK.
  • Where the ranges overlap they will often mix and create a natural hybrid called the Devony oak (Quercus x rosacea).
  • ​It is a large deciduous tree capable of growing up to 40m tall and can live for 500 to 1000 years.
  • The Sessile oak is a slow-growing tree, however it does have a faster growth rate than the English oak.  
  • It requires less light and is more drought tolerant than the English oak.
  • As a hill-bound species, it can be found up to altitudes of 1600m.
  • The Sessile oak is also known as the Welsh oak, Cornish oak, Irish oak or durmast oak.
  • It is a very important species and over 300 species of mixed wildlife rely on it for food and shelter.
  • The buds are rounded and orange / brown in colour and clustered on the twigs. 
  • Each bud has more than three overlapping, waxy scales that protect it during the winter time.
  • The buds of the English oak are not as prominent ​which helps with ID.
  • The leaves of Sessile oak are dark green, lobed, and have long yellow leaf stalks.
  • They are less deeply lobed than the leaves of the English oak.  
  • The leaves are around 7 to 14 centimetres in length and and 4 to 8 cm in width.
  • Like most oak trees the Sessile oak is monoecious which means that both the male and female flowers are on the same tree but different parts.
  • The male flowers are very showy catkins. which appear in April time.
  • They are yellow / green in colour and dangle freely on the wind.
  • The red female flowers are inconspicuous, and small in comparison and easily overlooked.
  • They are pollinated by the wind and on a mature tree there will be tens of thousands of flowers.
  • The fruit is the iconic acorn.
  • The growth habit of the Sessile oak acorns is different than the English oak as the acorns are borne directly on the twigs.
  • The acorns of the English oak are on short stalks and this really helps with ID.
  • The acorns start off bright green and as they mature they turn brown in colour.
  • Many animals rely on acorns and in some cases they help to spread them with their burrowing habits.
  • Squirrels and Jays are often seen in the early Autumn collecting and hiding acorns.
SIMILAR LOOKING TREES
ENGLISH OAK
LUCOMBE OAK
TURKEY OAK
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If there is anything out of place or wrong please contact me. Equally if there is anything you wish to add please let me know. The more information we have about Sessile oak the better. Many thanks!