A widespread species especially on western coasts. Found on wet rocky ledges and crevices. the foliose thallus is attached by a central holdfast. Pale grey to brown and dotted with ostioles of perithecia

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
Moberg et al. editors (2013) Nordic Lichen Flora, Volume 6: Verrucariaceae 1