Found on nutrient enriched rocks in coastal locations. Very similar to X. parietina. Rarely fertile and characterised by sparingly overlapping, discrete, crenulate-indented to strap-shaped lobes

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