The tiny Primula scotica – a primrose that grows in just three areas of Scotland – could be under threat from encroaching plantlife, a survey by Scottish Natural Heritage found.
According to the Royal Horticultural Society (RHS), the research shows that while the plant is flourishing in some areas, almost 40 colonies have disappeared in others.
Growing in Caithness, Sutherland and the Orkney Islands, the flower measures just 5cm in height and is easily pushed out by more vigorous rivals.
This appears to have been the case in the areas where the plant has run into difficulties, with Scottish Natural Heritage suggesting the sudden lack of grazing on the cliff-top locations could have allowed other plants to grow unchecked.
Survey manager Sally Ward explained: "The key to its success, or failure, is grazing in which grass is kept tightly cropped. The fortunes of Primula scotica rise and fall with livestock numbers."
Meanwhile a separate study has shown that a number of maple tree species may be in danger of extinction in their native China, the RHS reported recently.