Anamorph: not known.
Teleomorph: ascomata perithecia, scattered over the entire surface area of galled host tissue, 130–200 µm diam, ± globose with a papillate ostiole, initially hardly protruding from the host thallus but eventually more widely erumpent. Ascomatal wall 6–8 µm thick, hardly thicker in the ostiolar region, composed of several layers of radially compressed and vertically elongate tissue with cells 2-4 µm diam. Interascal tissue composed of frequently branched and anastomosed cellular pseudoparaphyses 2–2.5 µm diam, not gelatinized or blueing in iodine. Asci 86-105 × 12.5-16 µm, cylindric-clavate, thick-walled and fissitunicate, the apex thickened with a well-developed ocular chamber, not blueing in iodine, 8-spored. Ascospores uniseriately to partially biseriately arranged, 13.5-16.5 (-19) × 6.5-7.5 (-9) µm, cylindric-ellipsoidal, the apex and base obtuse to rounded, strongly constricted at the distinctly thickened median to marginally submedian septum, dark brown, thick-walled and verruculose at maturity, with a broad gelatinous epispore sometimes visible that may separate from the spore after discharge.
Assessed as of Least Concern by Woods & Coppins (2012), but listed as Nationally Scarce.
Causing galls on the thallus of Physcia caesia and occasionally other Physcia species.
Throughout the British Isles.