Arthoniaceae Arthonia apotheciorum # Lichenicolous fungus Chemical results negative. Epithecium K+ olive Can be common in the apothecia of Lecanora albescens and other members of the Lecanora dispersa group. BLS conservation evaluation: LC NS Black apothecia develop in the hymenium of the host lichen. Spores 1-septate, 9-15 x 3-5 µm. Paraphysoids 1.5-2 µm wide, the apices with dark pigmented caps. Microscope photograph below. Similar: Arthonia varians. Spores (1-)2-3 septate, on Lecanora rupicola

Microscope photograph

Arthonia apotheciorum
On Lecanora albescens. Studland, Church Knowle and Pamphill, Dorset. October 2012, March 2014, March 2020