Family: Lecanographaceae Species: Alyxoria viridipruinosa (Opegrapha viridipruinosa) Growth type crustose Photos: Co. Limerick and Co. Cork, Ireland. The thallus is almost absent or thin, powdery and grey-green (yellow when dried). Apothecia scattered, usually simple with thin, lateral thalline cover. Exciple black, raised, slit-like then exposed, yellowish inside margins. Disc +/- exposed, often with green pruina. Spores (3-)4-5 septate, (14-)15-19(-22) x (3-)4-5(-6) µm. Pycnidia frequent, with short bacilliform conidia. Micrographs below. Thallus K+ yellow near lirellae (in section) Since 1992 it has been recorded on the bark and lignum of Acer, Betula, Fraxinus, Quercus, Sambucus and Ulmus. Similar: A. varia (O. varia), whiter thallus without yellowish colour

Micrographs



Alyxoria viridipruinosa, Opegrapha viridipruinosa. August 2024