Forms an irregular, spreading crust of dark grey squamules, which is partly isidiate. A rarely recorded coastal species of the north-west. Found on soil and rock crevices in shade, often in coastal locations.
This species has a restricted distribution and is listed as Nationally Rare and a Priority Taxon for Biodiversity in Scotland

References: 
Smith, C.W. et al. editors (2009) The Lichens of Great Britain and Irelandd
Dobson, F.S. (2018) Lichens: an Illustrated Guide to the British and Irish Species