Order: Lecanorales       Family: Lecanoraceae Species: Lecanora intumescens Growth type crustose Photos: Foynes and Kilcolman, Co. Limerick, Ireland Whitish to pale grey thallus, sometimes with black prothallus. Apothecia reddish brown with swollen margins that become undulate and distorted and appear slightly powdery because of protruding hyphae (cortex is lacking). Margins contain small crystals and the epithecium has coarse yellow granules. Older apothecia become much larger in size. Spores 11.5-18 x 5-8 µm. Micrographs below. Widespread but scarce on smooth-barked deciduous trees. Chemistry: Thallus K+ yellw, C-. Exciple PD+ deep yellow or orange, UV+ pale orange or yellow Similar: L. argentata. Crystals in margins, no granules in epithecium

Micrographs



Lecanora intumescens. September 2010, August 2024