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.
On neutral to acidic bark of old trees e.g. Beech Fagus sylvatica , in old/ancient woodland. Also on vertical shaded granitic rock in west Cornwall. More recently (2002) found on Gorse Ulex spp. and the more acid barked trees on five or more metalliferous mining sites in west Cornwall.
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.