Acarospora privigna has apothecia less than 1 mm wide and an endolithic thallus. It has a hymenium height of (60–) 90–120(–130) μm, excluding the melanized epihymenial accretions of the Polysporina type. The hymenial gel is hemiamyloid (IKI+ red or blue turning red). Paraphyses are slender and profusely branched, 1.0–1.5 μm in width. Ascospores are mostly narrow ellipsoid, 4.0–5.0 × 1.0–1.5(–2.0) μm.
The species occurs usually on acid siliceous rock to diabase and other ultrabasic siliceous rock in full sun. It occurs at least in Europe and North America and is frequent in the Czech Republic at mostly elevations below 800 m.taxonomic classification: most frequented synonyms:Polysporina simplex
All records: 79, confirmed 69. One click on a selected square displays particular record(s), including their source(s).