A completely new species of plant for the British Isles has been discovered in the heart of England.
Cumbrian botanist Ann Boucher spotted the Mediterranean stinging nettle on a visit to Warwick and recognised it as out of place.
Warwickshire's plant expert James Partridge confirmed her identification as the Membranous Nettle, a species completely new to the British plant list.
Steven Falk, senior keeper of natural history for Warwickshire County Council, who helps maintain the country's data of local plants and animals said: "It is an exciting and rare event to find a plant completely new to the British Isles, which has the most intensively surveyed flora of any country in the world.
"It is even more astonishing to find one growing in such an urbanised location."
The nettle is growing beside a wall close to the Lloyds TSB Bank on Swan Street and is thought to be spreading across the Channel from northern France as part of the changes in the British flora resulting from international trade and climate change.
Seeds of foreign plants can arrive in Britain on the wheels of foreign lorries.