Order: Teloschistales       Family: Teloschistaceae Species: Flavoplaca citrina (Caloplaca citrina) s.lat Growth type crustose. K+ crimson / purple. Very common on walls, mortar and calcareous rocks, also sometimes found on bark, moss and soil. Recent work has shown that 'true' Caloplaca citrina does not occur in Britain and Ireland, the name having been wrongly applied to what is now known to be a complex of species. The aggregate comprises: Flavoplaca arcis, F. austrocitrina, F. citrina, F. dichroa, F. flavocitrina, F. limonia, Scythioria phlogina

Microscope photograph

Flavoplaca citrina sens lat. (Caloplaca citrina). March 2012