Horse chestnut Aesculus hippocastanum

Most commonly known as a conker tree, the horse chestnut was traditionally planted for its ornamental value. With its spectacular spring and early summer blossom and autumn conker crop, it is a tree for all seasons.

In Britain, the return to school after the summer holidays is synonymous with conkers. Originally played with cobnuts or snail shells, the use of the horse chestnut in the popular children's game was first recorded in 1848. Since 1965, the World Conker Championships have taken place every year in Oundle, Northamptonshire.

Also known regionally as 'obblyonkers', 'cheggies' and 'cheesers', the conker is the nut of the horse chestnut tree (Aesculus hippocastanum). As well as being tempting to pick up and play games with, the conker provides the horse chestnut with its method of germination. When the green spiny capsules fall off the tree in September, this shell is often already open and in this way the conkers are released. Those not collected for recreational use are often trodden into the ground, increasing the chances of a new tree growing.

When the horse chestnut was introduced to Britain in the 17th century, it was planted almost exclusively for its ornamental value, as it produces a spectacular white bloom in summer. Full-grown trees provide shade for livestock in the summer, but, conkers aside, it serves surprisingly little practical purpose as its wood is soft and weak and does not burn well.

The horse chestnut would probably be a more common sight than it already is but for the fact that it needs a lot of space to grow (mature specimens can attain a height of 35m or 115ft) and that its saplings need deep, moist soil in which to become established.