Description: Forms extensive black, finely-cracked crusts with abundant tiny warts (perithecia). Often extends well above HWM on rough coasts. The dominant lichen of the littoral 'Black Zone'. Frequently mistaken for spilt oil.

Key Identification Features:

• Extensive black, warted and finely cracked crusts
• Exclusively marine; dominant lichen of the 'Black Zone'.

Original text submitted by Michael J. Simms

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

iNaturalist: Hydropunctaria maura at iNaturalist World Species Observations database.