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
Widespread but very scarce and declining in S. England, with records from Herefordshire and Suffolk southwards. Elsewhere it is known only in Europe, from Denmark southwards to the Pyrenees. A report from Marion Island in the sub-Antarctic is probably based on misidentification.
Known in Cornwall only in Helford village, from the roof of an inn.
Habitat & Ecology
This species is well known for its pecular habitat, which is characteristically on old thatched roofs, although it is also known on wood, Juncus tussocks and the base of Molinia tussocks. The Cornish record was of scattered plants and very small patches on unshaded, damp, rather old thatch, low on a roof.
Survival of populations on thatched roofs depends on continued presence of old thatch, as discussed in detail by Hedderson et al. (2003).
None at the Cornish site. The species is treated as Vulnerable on the U.K. Red-list (Church et al ., 2001) and included in the UK BAP.
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.