Distribution: N - Ven, TAA (Dalla Torre & Sarnthein 1902), Lomb. C - Sar.
Description: Thallus crustose to subsquamulose, episubstratic, medium to dark brown, epruinose to weakly pruinose, consisting of up to 1(-1.5) mm wide, scattered to contiguous, orbicular to angular, flat or weakly convex areoles/squamules. Cortex 40-70 µm thick, overlain with an up to 30 µm thick epinecral later, lacking crystals; medulla white, without crystals. Apothecia lecideine, black, epruinose or faintly pruinose, 0.2-0.8 mm across, with a flat to convex disc and a thin, finally often excluded proper margin. Proper exciple grey in outer part, pale grey to colourless within, the pigmented parts K+ violet, N+ violet, without crystals; epithecium grey, K+ violet, N+ violet, 9-20 µm high; hymenium colourless, 50-60 µm high; paraphyses easily made free, 1.8-2.6 µm thick, the apical cells clavate, up to 8 µm wide, surrounded by a pigmented gel; hypothecium colourless, without crystals, 60-150 µm high. Asci 8-spored, cylindrical-clavate, surrounded by a gelatinous I+ blue coat, with a well-developed I+ blue tholus with a I+ darker blue tube and a well-developed ocular chamber, Bacidia-type. Ascospores 1-3-septate, hyaline, bacilliform or partly fusiform, 8.5-13(-16) x 3-5 µm. Pycnidia black, immersed. Conidia thread-like. Photobiont chlorococcoid. Spot tests: thallus K+ violet (cortex, in section!), C-, KC-, P, UV-. Chemistry: cortex, exciple and epithecium with the Sedifolia-grey pigment.
Note: a rarely collected lichen of continental-dry areas, found on steeply inclined seepage tracks of dolomite, rarely of compact limestone, almost always growing on cyanobacterial colonies when young.
Growth form: Crustose
Photobiont: green algae other than Trentepohlia
Reproductive strategy: mainly sexual
On otherwise dry surfaces with short periods of water seepage after rain