The descriptive text, below the map, is from the Cornish Red Data Book (2009). The map on this web page depicts the organisms distribution and shows the records made pre-2000 and those made since.
Range & Status
Native. Oceanic Temperate species. Found in south-western Britain from South Wales to Dorset, East Sussex, the Channel Islands and North Kerry in Ireland.
Recently thought to be declining in West Cornwall and increasing in East Cornwall. However more intensive recent recording has been re-finding old sites and it is still probably present in many previously recorded places where habitat is suitable. I.J. Bennallick has observed that populations known by him fluctuate in size and extent in a locality over time and this may give a false impression of decline. It has gone from almost all former sites on the Isles of Scilly and now is only found on the edge of one ditch.
Habitat & Ecology
Usually found in damp, shady situations, in woodlands and rush-pastures, especially where cattle poached, by small streams and water-filled ditches. It is also a feature of lawns in large estate gardens such as Trebah (SW72) and Heligan (SW94).
Loss of ditches and drying up of suitable habitat.
Many sites are unprotected.
I.J. Bennallick, S. Board, C.N. French, P.A. Gainey, C. Neil, R. Parslow, A. Spalding and P.E. Tompsett. eds. 2009. Red Data Book for Cornwall and the Isles of Scilly. 2nd Edition.Croceago Press.
The Cornish Red Data Book Project was led by the Cornwall and Isles of Scilly Federation for Biological Recorders (CISFBR). The full text and species accounts (minus the maps) are available on the CISFBR website.