Arthoniaceae Arthonia diploiciae # Growth type lichenicolous Chemical results negative Rare, parasitic on Diploicia canescens on church walls. BLS conservation evaluation: DD NR Thallus absent, clusters of small black apothecia produce brownish-grey spots on host thallus. Asci 4-spored, spores 1-septate, 8-11(-14) × 3.5-4(-5) µm. Microscope photograph below. Similar: Arthonia epiphyscia 8-spored asci, larger spores on Physcia spp. Arthonia punctella is parasitic on Diplotomma alboatrum

Microscope photograph

Arthonia diploiciae
St. Hubert's, Corfe Mullen, Dorset. January 2014