Horse chestnut and sweet chestnut trees have become a familiar feature of the Heath’s landscape.

Ham & High: A horse chestnut opens. Picture: David Holt/Flickr/Creative Commons (CC BY 2.0)A horse chestnut opens. Picture: David Holt/Flickr/Creative Commons (CC BY 2.0) (Image: David Holt/Flickr/Creative Commons)

After centuries embedded in English folklore, it is easy to assume these species have been a permanent feature of our woodlands. But they are officially "non-native" and although they share the chestnut name the two species are not even closely related, and their floral structures differ hugely.

Sweet chestnuts were introduced to the British Isles by the Romans, but today these trees are found throughout our woods and copses - especially in south-east England.

Mature sweet chestnut trees can grow to 35m and can live for up to 700 years. A great example sits opposite the Golders Hill park café.

Sweet chestnuts are a staple food source in many countries, but the UK's cool wet summers rarely allow the nuts to fully mature as they do in continental Europe.

Ham & High: Sweet chestnut trees on Hampstead Heath. Picture: Ed MathisonSweet chestnut trees on Hampstead Heath. Picture: Ed Mathison (Image: Archant)

The horse chestnut, or conker tree, is native to the mountainous forests of the Balkans. Believed to have been introduced into the UK around 1550, the tree has been widely propagated and planted in botanical gardens, parklands and country estates.

During the 20th century, they were also planted as street and parkland trees - as you can see throughout the Heath and in both Hampstead and Highgate villages.

Although this species looks out of place in some habitats, it does have a limited ecological value.

For example, it is a rich source of nectar and pollen to insects. Some moth caterpillars will feed on its leaves which in turn provide food for birds, such as the blue tit.

Older horse chestnuts often provide great homes for bats, such as the common pipistrelle.

The misunderstood creatures sometimes roost in old root pockets or under scaly plates of bark.

Less co-operatively, in recent years, an introduced moth, the horse chestnut leaf miner, has made its presence known. This can cause a brown speckling on the leaves from mid-summer onward, and though the pest is unlikely to kill a tree outright, it does make it unsightly.

The most famous use of horse chestnuts is the game of conkers, first played on the Isle of Wight in 1848. The Heath's conker contest takes place on October 18.

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