This lichen forms a thin grey thallus on Pinus bark with tiny epruinose black stalked apothecia 0.3–0.4mm high. The size of the cylindrical asci with uniseriately arranged spores is diagnostic at 30–35 x 4–5μm. This separates the species from stunted epruinose specimens of Calicium glaucellum, which has similar but longer and slightly narrower asci that are 35–41 x 3.3–4.5μm. A pine bark specialist, rarely recorded from lignum, first found in 2018 in native pinewood in Speyside and on introduced Scots Pine colonising glades in ancient Beech dominated pasture woodland in the New Forest. Also recorded from Oak lignum in the New Forest. Likely to occur elsewhere in Britain.
See Peksa (2006) Silva Gabreta 12: 51-56 https://www.npsumava.cz/wp-content/uploads/2019/06/sg12_2_peksa.pdf