This lichenicolous fungus has a hymenium height of (85–)100–130 μm with hemiamyloid gel and ellipsoid ascospores mostly 4–5 × 1.5–2.0 μm with apothecia usually less than 1 mm wide. It is possible that this species or some specimens identified as this species are conspecific with Acarospora privigna (illegitimate name Acarospora or Polysporina simplex). In that case A. subfuscescens would have two lifestyles as fungal parasite on lichens or as endolithic lichen.
The species is common in Europe on a variety of saxicolous lichens, on various siliceous rocks at lower and middle elevations. In the Czech Republic it occurs especially on Acarospora fuscata.
taxonomic classification:Ascomycota → Lecanoromycetes → Acarosporales → Acarosporaceae → Acarospora
most frequented synonyms:Polysporina subfuscescens, Polysporina lapponica auct.All records: 60, confirmed 60. One click on a selected square displays particular record(s), including their source(s).