Incertae sedis Homostegia piggotii # Lichenicolous. Photographs on Parmelia sulcata Usually occurs on Parmelia saxatilis but occasionally found on Parmelia omphalodes and Parmelia sulcata. Most frequently recorded from western Scotland, Wales and SW England. Black stroma on host thallus, each stroma with 5-12 locules containing the embedded perithecia. Asci 8-spored, spores brown, 3-septate, 18-22.5 x 5.5-8 µm and often slightly curved. Micrograph below. Similar: Abrothallus parmeliarum is also found on Parmelia species. Spores brown, 1-septate, 12-18 x 5-7 µm

Microscope photograph

Homostegia piggotii
On Parmelia sulcata. Studland Heath, Dorset. March 2015