Sphaerellothecium cinerascens

Lichenicolous on Cladonia parasitica, but also found once on Cladonia incrassata, on Oak lignum in old woodland. The fungus has tiny perithecia 40 – 70 µm diameter found on the squamules of the lichen, but is very conspicuous, as it stains the host tissues a blue-grey colour over sizeable patches. The spores are brown, 1 septate and 9 –11.5 × 3–4 µm.  Only otherwise known from the western Pyrenees in Europe and appears very rare in Britain. Also recently recorded from cloud forest in the Seychelles. Recorded once in Dartmoor and twice in the New Forest by 2020. In the latter extensive searching, on passing, over three years in old growth woodlands with massive populations of Cladonia parasitica has produced only two locations with the parasite.