Distribution: C - Laz (Llop & al. 2007), Sar (Llop & al. 2007. S - Si (Llop & al. 2007).
Description: Thallus crustose, episubstratic, grey-green; continuous to rimose-areolate. Apothecia lecideine, sessile, pale pink to orange, (0.25-)0.45-1.1(-1.4) mm across, unevenly white-pruinose, with a slightly concave to flat disc, and a concolorous to slightly paler, initially thick and raised, later often almost excluded proper margin. Proper exciple colourless to pale yellow, prosoplectenchymatous, of sparsely branched and anastomosing hyphae with rectangular lumina, the terminal cells oblong to globose, (1.6-)2-4(-6) μm wide, the marginal zone with evenly distributed colourless crystals soluble in K, the medullary part rarely with clusters of colourless to yellowish crystals dissolving in N, K+ intensifying yellowish, N-; epithecium poorly differentiated, pale yellowish brown, with unevenly distributed yellowish to reddish orange crystals dissolving in K but not in N, K-, N-; hymenium colourless, (50-)60-75(-85) μm high; paraphyses coherent, mostly simple and not anastomosing, (0.8-)1-1.2(-1.6) μm thick, the apical cells oblong to globose, 1.6-2.4(-3.2) μm wide; hypothecium colourless to yellowish, K+ intensifying yellowish, N-. Asci 8-spored, cylindrical-clavate, surrounded by a gelatinous I+ blue coat, with a well-developed I+ blue tholus, a I+ darker blue tube and a well-developed ocular chamber, Bacidia-type. Ascospores 5-8(-9)-septate, hyaline, needle-like, 41-53 x 2-3 μm. Photobiont chlorococcoid. Spot tests: thallus K-, KC-, C-, P-. Chemistry: thallus without lichens substances; apothecia with the Rubella-orange pigment.
Note: a recently-described, Mediterranean-Macaronesian species, related to B. fraxinea and B. rubella, bound to humid situations in forests, such as in bottoms of valleys or ravines, mostly in coastal, humid situations. In the original description the species was misspelled as “thyrrenica”.
Growth form: Crustose
Photobiont: green algae other than Trentepohlia
Reproductive strategy: mainly sexual
Most common in areas with a humid-warm climate (e.g. most of Tyrrenian Italy)