May is the perfect month to enjoy the flowering of the horse chestnut tree. This stately tree is now in blossom across much of the Dales, lighting up the countryside with its candelabra flower-spikes.

Most people do not realise that the horse chestnut is not a native British tree at all. It was introduced here from the Balkans in the sixteenth century and for a couple of hundred years was confined to the grounds of large country estates. Only in the 1800s did the tree become more widely known to the general public when it was planted in public parks and villages.

The horse chestnut is now one of most popular trees of the countryside, seeding freely and appearing as if it were a native species. If you have never looked closely at its impressive flower spikes, this is the month to make your acquaintance. In the common form of the species the petals are white, tinged with pink, but in a hybrid variety a stunning pink can be found.

People have benefited from the horse chestnut for many centuries and recent research has helped to cast light on their medicinal properties. Long-used by Turkish farmers to treat sprains and bruising in horses, the tree has been found by German scientists to contain a substance called aescin. Such is the effectiveness of aescin to treat sprains and bruising - and also help with blood circulation - that the Forestry Commission here is considering planting entire horse chestnut forests to meet the predicted demand from the pharmaceutical industry.

The tree's association with horses, however, goes far beyond its common name and medicinal use. In many countries the fruits are used to feed horses and cattle, after first being soaked in water to remove the bitter taste and then ground to a meal.

Though mildly poisonous to humans, in times old the bark of the horse chestnut was also soaked to produce a preparation that was used to treat fevers, and applied externally to ulcers. The fruits were also used to counteract the effects of rheumatism and neuralgia. Horse chestnuts are still used to deter moths and are added to shampoos to enhance their natural image.

But, of course, most people's affection for horse chestnuts, however, comes from their amazing fruits which we tend to know as "conkers", though I much prefer the local name "obblyonkers". Because of their association with peacefulness and their ability to provide impressive shade in the summer, they were frequently planted in villages. This meant that many children discovered the autumn pleasures of playing conkers close to their homes.