Dutch elm

But Dutch elm disease, an invasive fungus spread by bark beetles to which the native trees had no defense, has decimated the elm by tens of millions across the continent.

The ash trees of Iowa City, planted to replace elms felled by Dutch elm disease, are now succumbing in turn.

In the middle of the 20th Century, three species of another fungi under the genus Ophiostoma swept through North America and Europe, sickening trees with what's known as Dutch elm disease.

Ms Franklin said: "The Beauly elm has succumbed to Dutch elm disease."

This is precisely what happened with the elm, ruined by the beetle that brought Dutch elm disease.