Description: Thallus calcified and encrusting with thick margins and a smooth matt surface producing erect branches which may break off and persist as unattached plants.

Habitat: In maerl beds with broken shells in the sublittoral.

Distribution: Very rare, recorded from only a few counties in Ireland, Wales and the Channel Islands, old records from Scotland. Europe: Mediterranean, France (Brittany) and Spitzbergen.

Distribution Map from NBN: Lithophyllum fasciculatum at National Biodiversity Network mapping facility, data for UK.

iNaturalist: Lithophyllum fasciculatum at iNaturalist World Species Observations database.

WoRMS: Lithophyllum fasciculatum at World Register of Marine Species.