Xanthopyreniaceae Didymellopsis collematum Growth type lichenicolous Photographs on Collema tenax var. ceranoides Lichenicolous on Collema s. lat., including Collema glebulentum, Scytinium turgidum and Lathagrium auriforme. Very few records but probably under-recorded as can be difficult to see on the host thalli. Scattered or clustered dark-brown to blackish perithecia (pseudothecia) on host thalli. Asci 6-8 spored, 80-100 × 13-15 µm, spores hyaline, 1-septate, 20-26 × 5-10 µm. Micrographs below. Similar: Didymellopsis pulposi appears to be more frequent but has smaller asci (40-70(-90) × 10.5-13.5 µm and spores (13-22 × 5-7 µm)

Micrograph



Didymellopsis collematum
Photographs: Broadstone, Dorset. November 2025