Description: This common crustose lichen of both smooth and rough tree bark has a thin, smooth-mottled, slightly cracked, grey to grey-green thallus bearing crooked discs with thick, irregular margins (like a punctured car tyre) emerging from sunken warts. It can occur on trees with its namesake, Pertusaria pertusa but, unlike that species, lacks the conspicuous zoned margin and neat, pinpricked discs.

Key Identification Features:

• Clumsy-crooked discs with scurfy-deflated margins
• Barely zoned border to the thallus.

Original text submitted by Vince J. Giavarini

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

iNaturalist: Pertusaria hymenea at iNaturalist World Species Observations database.