Lichens : Caliciales : PhysciaceaeLichens

Physcia tribacioides Nyl.

Description: This epiphyte is not unlike Physcia tribacia (described elsewhere) but with more pliable lobes and scattered, floury, subglobose soralia. This Michelangelo of Physcia lichens, with its elegant curves and lines, decorates the wayside trees of Waterford and Cork like a rare alabaster carving. It lacks the white flecks and big, convex soralia of Physcia caesia (1.2mm diam. compared with up to 2mm in P. caesia) and occupies less nutrient-enriched habitats. Extreme south of Ireland; both wayside and well-illuminated woodland trees. A species to watch as it would be expected to spread slowly north with increasing global warming.

Key Identification Features:

  • Pure blue-grey thallus, irregular in outline, with abundant laminal soralia
  • Thallus flattened, soralia subglobose not granular.

Original text submitted by Vince J. Giavarini

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

iNaturalist: Physcia tribacioides at iNaturalist World Species Observations database.

 Giavarini, Vince J., Simms, Michael J., & Davey, Simon, 2026. Physcia tribacioides. Nyl.. [In] Lichen Ireland.
https://www.habitas.org.uk/lichenireland/species.php?item=18937. Accessed on 2026-11-12.