Lichens : Lecanorales : StereocaulaceaeLichens

Stereocaulon evolutum Graewe

Description: This tough, light grey, cushion-forming, richly branched, arching, rock and soil-inhabiting lichen is a familiar species in upland Ireland. In Stereocaulon stems (pseudopodetia) support a grey mass of coralloid branches called phyllocladia. In S. evolutum these are flattened as if hammered out by a silversmith with numerous similarly flattened finger-like lobes. The branches arch over the thallus like a splayed hand waiting to pounce. The thallus is KC + violet (a spot of KOH followed soon after by a spot of fresh bleach). Throughout Ireland.

Key Identification Features:

  • Grey and cushion-forming with flattened branches linked to finger-like tips arching up over a thallus (which can sometimes exceed 10cm diam.)
  • The thallus tests KC + violet; in S. vesuvianum the branches are not flattened and have dark grey spots at their centres.

Original text submitted by Vince J. Giavarini

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

iNaturalist: Stereocaulon evolutum at iNaturalist World Species Observations database.

 Giavarini, Vince J., Simms, Michael J., & Davey, Simon, 2026. Stereocaulon evolutum. Graewe. [In] Lichen Ireland.
https://www.habitas.org.uk/lichenireland/species.php?item=19058. Accessed on 2026-11-12.