Many people have heard of Dutch elm disease, but few people are familiar with a tree that once helped define the English landscape.

The fungus almost wiped out an estimated UK population of around 30 million trees.

But the Conservation Foundation thinks there could be more mature elms in parks, gardens and our countryside than we think.

It is calling on the British public to become elm detectives, search for the UK’s surviving elms and record them on its interactive map.

There are currently almost 150 elms identified by experts and enthusiasts.

The tree has distinctive blossom, and mature trees have a distinctive shape familiar from many old photographs.

Watford Observer:

Elm trees have distinctive blossom

Elm sightings can be logged by uploading photographs of the tree with its location and as much other information as possible, including pictures of the shape and bark.

Watford Observer:

The saw-toothed leaves appear later in the season

When the leaves come through later in the season, the elm detectives are asked to add a photograph to their online record for the expert panel to identify the species.

Watford Observer:

The bark also helps identify elm trees

Postings are being moderated by elm experts and researchers who will identify the species.

Foundation director David Shreeve said: “Our foundation grew out of an elm project over 30 years ago and since then we have undertaken a number of initiatives to show that, despite the huge loss of elms due to disease and development, they are still very much around.

"Now, with modern technology, anyone will be able to see just where the UK’s elms are and hopefully, as a result, even more healthy, mature trees will be discovered and added to our map.”

The foundation's interactive map can be seen at www.conservationfoundation.co.uk/elms/map.