Elm trees used to be common throughout Britain, but were almost wiped out in the 1970s by Dutch Elm Disease, a fungal disease spread by the elm bark beetle. It is called Dutch Elm disease because it was identified in the Netherlands, not because that was where the disease originated. The strain of the disease which decimated the British elm population came from America in a consignment of logs.
A few colonies survive intact (such as a colony in Brighton), and some others have evolved resistance to the disease. In many locations suckers survive, which can grow for a few years before succumbing to the fungus.
The elm tree has very rough bark, and produces tassel-like purple catkins in late winter.