F amous tree-lined avenues such as the Mall in London could be rendered unrecognisable for decades by a catastrophic tree disease spreading across Europe.
The head of the UK's largest tree management body has warned that it is only a matter of time before "plane tree wilt", also known as canker stain of plane, reaches British shores.
The disease is currently spreading north through France and is reported to have reached Paris.
With sturdy trunks and a lush green summer canopy, plane trees account for more than half of London’s tree population and are synonymous with Hyde Park, the Victoria Embankment, as well as other major cities.
The disease, which has already ruined miles of the historic tree-lined Canal du Midi in southern France, is not native to Europe and is thought to have arrived in Italy in wooden US ammunition crates during the Second World War.
The spread began when the crates rotted and airborne spores came into contact with Italian trees in the 1970s.
Plane wilt can also be transmitted through contaminated tools such as saws and chainsaws, through watercourses and where tree roots intertwine.
The disease attacks the vascular system and prevents water circulating, killing the tree and resulting in lifeless hanging from branches.
Jago Keen, Chairman of Arboricultural Association, said the lack of plant diversity in British cities, and in particular London, left them acutely vulnerable.
“If the disease gets to London the impact would be catastrophic,” he said. “It would kill a large number of plane trees very quickly. “The Mall would disappear practically overnight, as well as Broadway and Berkeley Square. “They would take a long, long time to replace. “You would have to cut the dead trees down, then replant and wait for them to grow. “A lot of the trees in The Mall are 60 to 70 years old, and in Berkeley Square they are 100 plus. “We would have to wait that long to restore the current look.” He added: “We are very concerned because we do have something of a track record of letting diseases get in here.”
The main symptoms are large numbers of desiccated trees, leaves going grey and orange but staying on the canopy.
Any suspected sightings of the disease in London should be reported to a local tree officer, contactable via the London Tree Officers' Association.