Arthoniaceae Arthonia parietinaria # Lichenicolous on Xanthoria parietina Probably widespread in lowland areas on thallus and apothecia of Xanthoria parietina. Thought to be more frequent than Arthonia molendoi Ascomata usually in clusters of 10-50. Asci are 8-spored, the spores hyaline, 1-septate, (9-)10-12(-13.5) x (3-)4-5(-6) µm. The upper cell usually broader and slightly shorter than the lower. Micrographs below. Similar: Arthonia molendoi, ascomata single or in groups of 2-5

Micrographs



Arthonia parietinaria #
On ,Xanthoria parietina, Corfe Mullen, Dorset. February 2020