The county of Cumbria contains much of the mountain habitat in England, including the Lake District National Park, Howgill fells and the higher parts of the North Pennines.
The flora of the Cumbrian mountains is generally poor due to a combination of acidic rocks and many decades of overgrazing by sheep. However there are a few places where calcareous rocks prevail and a splendid assemblage of arctic alpine plants can be found on crags and ledges inaccessible to grazing sheep.
A visitor to the fells will generally be walking in a landscape dominated by Mat Grass Nardus stricta which has formed due to overgrazing by sheep. In a natural environment, Mat Grass naturally occupies damp hollows, other grasses, sedges, and heath vegetation dominating the drier areas. Because Mat Grass is unpalatable to sheep, in a heavily grazed environment like the Lake District better tasting plant species are preferentially eaten leaving the Mat Grass to proliferate resulting in its dominance over large areas of upland.
It is unsurprising that there are few butterflies to be found in such a cold, wet and generally inhospitable environment. Some habitat generalists and migrants such as the Small Tortoiseshell and Red Admiral can frequently be seen in transit across the summits of the highest mountains Clouded Yellow can also sometimes be seen on the western Lake District fells located close to the coast in a good immigration year.
Small Heath are to be found on the mountain grasslands right across the county but it is the Mountain Ringlet, Britain's only true montane butterfly that most butterfly enthusiasts come to see in our mountainous environments.