Mystery arrival of a tree now part of love-hate relationship
IT IS probable that no one would ever vote for the sycamore as Britain’s favourite tree when the competition includes mighty oaks and stately horse chestnuts.
A capacity for rampant growth as well as a prejudice resulting from it being a non-native species has created the perception that the tree is akin to invasive plants like Japanese knotweed and Himalayan balsam. Sycamores are also unloved by people who park cars under their branches and find a tacky coat left on windscreens, a so-called ‘honeydew’ produced by tiny aphids. In the past, sycamores were famously blamed by British Rail as the source of ‘the wrong sort of leaves’ on lines in autumn, which apparently made trains prone to skidding.
How the tree came to the UK is still a mystery. A native of central and southern Europe, the sycamore is thought to have arrived here around the 15th and 16th centuries although some believe it was introduced by the Romans, the evidence for this being traces of sycamore wood found by archaeologists at Langton Villa, a Roman site near Malton.
Today a landscape without sycamores is hard to imagine. In upland areas of Yorkshire they are often seen huddled around isolated hill farms in an otherwise treeless scene.
And aversion to the tree is certainly not universal, as shown by the number of Sycamore Cottages in villages and the naming of residential streets like Sycamore Terrace in York.
Walking along the towpath of the Leeds-Liverpool Canal a couple of weeks ago, I saw a large number of ink-like blots on the leaves of sycamores and wondered if they were the first symptoms of disease. After all, we have become used to the decimation of trees since Dutch elm disease was spread by bark beetles in the 1980s
That was followed by the felling of horse chestnuts because of three afflictions: bleeding canker, then chestnut leaf blotch spread by a tiny gnat which defoliates trees after turning leaves brown the moment they sprout, and more recently the grubs of leaf miner moths from the Balkans chomping through leaves and reducing their ability to photosynthesise.
In the last decade we have also lost many ash trees because of the chronic fungal disease known as ash dieback. This has been especially noticeable in the Yorkshire Dales. However, it was a relief to discover that while sycamore leaf blots – evidence of a disease officially termed tar spot – can make leaves fall prematurely, it probably won’t kill those trees affected.
But sycamores are not altogether in the clear. A condition known as sooty bark originated in the USA, and in the UK was first seen in Essex before spreading northwards. A fungus causes the shrivelling of leaves which leads to the death of boughs and eventually the whole trees. As the bark loosens and falls away a sooty layer of black spores is revealed, and these spread the disease.
Sooty bark is believed to lie dormant until triggered by periods of prolonged hot weather, so climate change may be bad news for the sycamore.