Description: This is an acid rock lichen of stony waste and spoil. It most commonly occurs as small, scattered convex lumps (areoles to 1mm diam.) covered in greenish soredia that are C (fresh bleach) + red. It can also have a form resembling rather congested aggregations of rounded squamules. The brown discs are not always present. Central and eastern Ireland mainly.

Key Identification Features:

• Scattered squamules with greenish soredia
• Thallus C+ red; acid dusty sites: old quarries, mines, spoil, and in urban areas, brick.

Original text submitted by Vince J. Giavarini

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

iNaturalist: Trapelia obtegens at iNaturalist World Species Observations database.