Horse chestnut (Aesculus hippocastanum)

Spiky cases, gleaming seeds, celebrated by children. Horse chestnuts, with their mahogany-bright conkers, are the very essence of autumn.

Common name:
Horse chestnut

Scientific name:
Aesculus hippocastanum

Family:
Hippocastanaceae

Origin:
Non-native

Mature horse chestnut trees grow to a height of around 40m and can live for up to 300 years. The bark is smooth and pinky-grey when young, which darkens and develops scaly plates with age. Twigs are hairless and stout; buds are oval, dark red, shiny and sticky.

What does horse chestnut look like?

Leaves:
The palmate leaves comprise 5–7 pointed, toothed leaflets spreading from a central stem.

Flowers
Appearing in May, individual flowers have 4–5 fringed petals, which are white with a pink flush at the base.

Fruits:
Once pollinated by insects, each flower develops into a glossy red-brown conker inside a spiky green husk, which falls in autumn.

Where to find horse chestnut:
Horse chestnut is native to the Balkan Peninsula. It was first introduced to the UK from Turkey in the late 16th century and widely planted. Though rarely found in woodland, it is a common sight in parks, gardens, streets and on village greens.

Value to wildlife :
The flowers provide a rich source of nectar and pollen for insects, particularly bees. Caterpillars of the triangle moth feed on its leaves, as does the horse chestnut leaf-miner moth whose caterpillars provide food for blue tits. Deer and other mammals eat the conkers.

Mythology and symbolism:
There is little British folklore associated with the tree – probably due to it being an introduced species. However, games of conkers have different rules in different parts of the country, and have their own jargon which often requires repeating rhymes or rituals to decide who goes first.

Uses of horse chestnut:
The most famous use of horse chestnut is in the game of conkers. The first record of the game is from the Isle of Wight in 1848.

Horse chestnut timber is a pale creamy-white to light brown, with a smooth, soft, fine texture. It’s not very strong and is therefore not used commercially, but its soft texture makes it ideal for carving.

Other uses of the conkers include horse medicines, as additives in shampoos, and as a starch substitute. Chemicals extracted from conkers can be used to treat strains and bruises. There’s hearsay that if you place conkers around your house it will keep spiders away, but there’s no scientific proof that this is the case.

The Victorians wrote recipes for making conker flour. The seeds were shelled, ground and then leached to remove bitter flavours. It’s not a common practise these days and if consumed in excessive quantities conkers are mildly poisonous.