English Oak Tree

Probably the best known tree in Britain and an important feature of the English landscape.

They live for hundreds of years and have always been important for their timber. The wood has been used to build ships, houses and furniture, but is also renowned for its use in casks for maturing wines and spirits.

The fruit of the oak tree is the acorn which appears usually in September and is very popular with squirrels.

The oak is deciduous but loses its leaves very late in the year.

Sometimes, strange structures appear on the acorns and leaves of an oak tree. The Oak Apple Gall above is caused by the wasp, Biorhiza pallida. These oak apples were about 5 cm diameter and appeared as the leaves were appearing in May.

There are various types of gall and the picture on the left shows a Knopper Gall, where the acorn has become yellow, distorted and sticky. These are caused by the gall wasp, Andricus quercuscalicis which lays its eggs inside the acorn and causes it to mutate.

These wasps do not usually cause damage to the tree and are nothing to worry about.