Ascomycota       Incertae sedis Species: Xanthoriicola physciae Lichenicolous fungus parasitic on Xanthoria parietina Photos: Co. Cork, SW Ireland. Brown, septate hyphae immersed in the host apothecia. Dark conidiophores produce warty, brown, globose conidia that turn the apothecia and then the surrounding dead thallus black and 'sooty' in appearance. Conidia 4-6 x 4-6 µm. Micrographs below. Widespread and can be locally common. It has been recorded on both Xanthoria parietina and X. polycarpa. Similar: Arthonia parietinaria is found on Xanthoria parietina, the spores 1-septate

Microscope photographs



Xanthoriicola physciae on Xanthoria parietina. May 2012