Lecanographaceae Alyxoria viridipruinosa (Opegrapha viridipruinosa) Growth type crustose. Chemical results: Thallus K+ yellow near lirellae (in section) Since 1992 it has been found on bark and lignum of Acer, Betula, Fraxinus, Quercus, Sambucus and Ulmus. A recently described species and probably more widespread than the maps indicate Thallus almost absent or thin, powdery and grey-green (yellow when dried). Apothecia usually simple with thin, lateral thalline cover. Exciple black, raised, slit-like then exposed, yellowish in margins. Disc +/- exposed, often green pruinose. Spores (3-)4-5 septate, (14-)15-19(-22) x (3-)4-5(-6) µm. Pycnidia frequent, conidia bacilliform 2.5-3 x 1-1.3 µm, Micrographs below Similar: Alyxoria varia (Opegrapha varia)

Micrographs





Alyxoria viridipruinosa (Opegrapha viridipruinosa)
Photographs: Wincombe Park, Wiltshire. May 2024. Poole, Dorset, April 2025