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. Suboceanic Temperate species. Scattered across Britain and Ireland.
Formerly more widespread in Cornwall, its decline is continuing. Apart from two sites in West Penwith and Cargenwen Reservoir (SW63), the remaining populations are on The Lizard and in the mid-Cornwall moors.
Habitat & Ecology
Pond margins and shallow, muddy pools, especially on wet trackways. Sometimes found as a pioneer species in newly created shallow, muddy ponds. Some disturbance is beneficial to keep habitats open.
Scrub encroachment, drying of pools and the surfacing of muddy tracks.
Many of the sites as SSSI and NNR.
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.