Description: Known in Ireland only from one site in County Clare, this is a grey, crustose lichen of basic mica-schists or similar rocks with short thick, fan-shaped lobes and black discs. The Pd+ faint orange reaction of the thallus is significant. It is an unmistakable species of mountain cliffs.

Key Identification Features:

• Near-complete grey rosettes 2–3cm diam., of short, thick fan-like lobes with black discs
• Tests Pd+ faint orange.

Original text submitted by Vince J. Giavarini

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

iNaturalist: Pannaria hookeri at iNaturalist World Species Observations database.