Description: Look out for this species on damp granitic surfaces. The small crustose thallus (a few cm at most) has a distinctive ‘jizz’: a polished olive green sheen to the areoles (tiny islands of thallus), surrounded by a jet black rim. This combination is never met with again in other Irish lichens. The whole forms a beautiful mosaic of black and dark green like a piece of stained glass. Discs are black, small. Hunt for it on granites besides waterfalls and gorges and on large damp boulders that have come to rest. Schaereria fuscocinerea comes closest to this species but has blacker areoles with no evidence of green pigmentation in the thallus. In Ireland, the species has been recorded from the Dingle peninsula in County Kerry.

Key Identification Features:

• Thallus with shiny dark green areoles surrounded by a thin black rim
• An attractive crust of damp, granitic outcrops and boulders.

Original text submitted by Vince J. Giavarini

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

iNaturalist: Claurouxia chalybeioides at iNaturalist World Species Observations database.