Paul Eccleston, The Telegraph 7 Aug 08;
A warning about 'ragwort hysteria' has been issued by conservation agencies after reports of a boom in the potentially fatal weed.
The warm and wet summer has led to more sightings of the yellow-flowered Common Ragwort which can kill horses and other livestock if eaten in large quantities.
But it only poses a threat on pasture or farmland where animals are kept and elsewhere it provides a vital life-support system for insects.
Growing in gardens or on wasteland it is harmless and enormously important to pollinating insects such as bees and wasps.
The distinctive yellow weed Senecio jacobaea grows to waist height and can survive for years as seeds in the ground until conditions are right for it to flower. Recent weeks of warm sunshine interspersed by bouts of heavy rain have been perfect for it to flourish.
Britain's Open Spaces Society chairman Rodney Legg said that in 50 years of walking the countryside he had never seen so much ragwort.
"There are huge swathes of it and it is very toxic and potentially very dangerous," he said.
"It is catered for under the Weeds Act 1959 and landowners have to remove it if it becomes a problem. I always used to pull it up and take it away, but there is so much now it is not really worth it."
Although ragwort can be dangerous and needs to be controlled near livestock, urban myths have grown up about its capacity to kill.
It contains compounds that are poisonous to most vertebrates but these only become active when it has been changed by chemicals after it has been ingested. When it has been eaten in large quantities it can cause cumulative and potentially fatal liver damage.
Ragwort is at its most dangerous when it is already dead or dying and becomes accidentally caught up during mowing and hay-making.
But a horse or cow would have to eat as much as 25 per cent of its own body weight of ragwort to be poisoned.
The charity Buglife says that many insects - bees, wasps, butterflies and moths - and other invertebrates are totally dependent on Ragwort for food.
Director Matt Shardlow said: "Ragwort is a native part of our ecosystems and directly supports more than 40 other species, in addition it is an important nectar source, helping to sustain what is left of our natural pollination services.
"There is a lot of emotive hyperbole about the dangers of ragwort and this should be viewed with a discerning eye. It would be a tragedy if it is pulled out of the ground wherever it is seen."
Matthew Oates, Nature Conservation Adviser at the National Trust, said: "Ragwort, although a threat to livestock, has an important role to play in the biodiversity of our countryside.
"Insects absolutely love it, and it can happily exist in areas set aside for nature conservation as long as these areas are not next door to grazing animals, especially horses.
"It is a hugely difficult species to control and neither the technology nor the resources currently exist to control it effectively."
