Thallus to 5 cm diam., often forming extensive patches, crustose, rimose or areolate. Prothallus indistinct. Areoles to 0.2 (-0.5) mm diam., matt, usually angular, flat to convex, ochre-brown to deep orange-brown. Soredia and isidia absent. Photobiont chlorococcoid.
Anamorph: no information available.
Teleomorph: ascomata apothecia, to 0.5 mm diam., not pruinose, angular to flexuose, persistently flat. Disc usually umbonate or subgyrose, uneven. True exciple distinct, brown-black, K–. Epithecium olive-green or green-black, K–. Hymenium hyaline to faintly green in the upper part. Hypothecium dark brown, K–. Crystals and granules absent from the apothecia. Interascal tissue of pseudoparaphyses, strongly conglutinate, richly branched and anastomosed, apical cell distinctly thickened and pigmented. Asci clavate to cylindrical, fissitunicate, with a well-developed tholus that is K/I– in the lower part and K/I+ blue near the apex, lacking an ocular chamber, 8-spored. Ascospores 12-18 × 3-7 μm, clavate, mainly 3-septate, persistently hyaline, fairly thick-walled, smooth, surrounded by a gelatinous sheath.
Chemistry: lichen products not detected by TLC.
Assessed by Woods & Coppins (2012) as of Least Concern.
Mainly in northern and western parts of the British Isles. BLS map here.
On siliceous rocks rich in iron minerals; locally frequent.