Description: This is not a lime specialist like the scaly (squamulose) Toninia aromatica but needs some base-enrichment to thrive. The lichen is crustose and cracked into tiny grey-brown islands of thallus which do not possess the white flecks so characteristic of T. aromatica (described elsewhere). Coastal in distribution, it grows in cliff crevices by the sea. It is only rarely recorded from Ireland.

Key Identification Features:

• Thallus crustose, brownish, cracked like a mirror and growing in tiny rock crevices near the sea
• The thallus is without white flecking; often on acid rocks with some base enrichment.

Original text submitted by Vince J. Giavarini

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

iNaturalist: Toniniopsis mesoidea at iNaturalist World Species Observations database.