Horse chestnut facing serious threat

THE horse chestnut is one of the largest flowering trees growing in the temperate zone, often exceeding 30 metres in height with a huge, domed crown.

It is also one of the most magnificent, particularly in May and June when it’s in flower.

Unfortunately, it’s been in the news for all the wrong reasons recently because so many specimens are dying of a bacterial disease called bleeding canker.

Efforts are being made to find some sort of cure or treatment, but so far without success, so there is a possibility we may have to say goodbye to this fine tree. The story of its arrival in these islands is quite an interesting one. In 1576 the Holy Roman Empire’s ambassador to Constantinople sent some conkers back to Vienna. These were planted and grew into the now familiar tree. When horse chestnuts are young they grow rapidly, for a deciduous tree.

People were impressed by the large, shiny leaves like the fingers of a hand, by the conkers in their armoured cases and, above all, by the flowers, those 20 centimetres ‘candles’ of white and pink. By 1615 horse chestnuts had reached Paris, again from seed sourced in Constantinople, and there is a record of one in London in 1633. We don’t know exactly when the first horse chestnut was planted in Ireland, but it was almost certainly in the late 1600s.

All the seeds had been bought in markets in Constantinople, which is now Istanbul, so there was an assumption that the tree was native to Asia — eastern Turkey, perhaps, or maybe further east in what was then Persia and is now Iran. The French for the species is ‘marronier d’Inde’, reflecting this belief. But over the centuries nobody could find any wild specimens and there was speculation that they might have become extinct.

In the 1790s an English gentleman explorer called John Hawkins reported that horse chestnuts grew wild in the Pindar Mountains in Greece. But the botanical establishment of the day was so convinced of the Asian origin that he was laughed at.

By 1879 the Ottoman Empire had given back parts of northern and central Greece to the Kingdom of Greece, making it a much easier and safer place to visit. A German called Theodor von Heldreich, then director of the Botanic Gardens in Athens, at first he disbelieved reports from his local guides that chestnuts with large white flowers were growing wild in the mountains. But he climbed up into a wild, remote and totally uninhabited area and found the trees growing in shady, humid ravines at an altitude of between 1000 and 1200 metres.

Subsequent research has clinched the fact that the horse chestnut is a native European species, growing in small numbers in mountain valleys that span the border between Greece and Albania. In the wild the species is quite unlike the magnificent parkland specimens and street trees that we are familiar with. It tends to be stunted and short-lived.

The decorative value of the tree is probably not the only reason it became popular. When the first seeds came from Constantinople they were accompanied by the information that they had important veterinary properties. They were fed to horses to cure coughs and other respiratory problems. Horses were the most important form of transport at the time so this was an added attraction.

The game of conkers, known as ‘kingers’ in some parts of the world, has been placed in jeopardy by the disease. It seems to be of 19th century origin, the first record of a game is from the Isle of Wight in 1848. There are both World and Irish Championships.

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