Distribution: C - Tosc (Llop 2010), Marc (Llop 2010), Laz (Llop 2010), Sar (Llop 2010). S - Bas (Llop 2010), Pugl (Llop 2010), Si (Llop 2010).
Description: Thallus crustose, greyish green, continuous to rimose-areolate, with a granulose surface. Cortex colourless, paraplectenchymatous, 10-20 μm thick; algal layer continuous. Apothecia yellow-orange to pink-orange, more rarely pale cream to translucent, (0.15-)0.2-0.55(-0.65) mm across, with a flat to convex disc and a weakly prominent, slightly paler proper margin. Proper exciple colourless to pale yellow, prosoplectenchymatous, with a dense textura intricata, 25-30 μm thick, of radiating, branched and anastomosing hyphae, the lumina 4-10(-12) x 1-1.5(-2) μm thick, the terminal cells slightly obovate to globose, (2-)2.5-5.0 μm wide; epithecium not differentiated from hymenium; hymenium colourless, (40-)45-60(-65) μm high; paraphyses coherent, simple, not anastomosing, 1-1.5 μm thick at base, the apical cells 1.5-3.5(-4.0) μm wide; hypothecium colourless to pale yellow, prosoplectenchymatous, c. 30 μm high, with a loose textura intricata; subhymenium colourless to pale yellow, paraplectenchymatous, 10-15 μm thick, with textura globularis. 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 3-7-septate, hyaline, needle-like, tapering to one end, (24-)28-40(-42) x (1-)1.5-2 μm. Pycnidia rare, colourless, immersed in the thallus. Conidia filiform, straight, 5-10- septate, (40-)45-60 x c. 1 μm. Photobiont chlorococcoid. Spot tests: thallus K-, C-, KC-, P-. Chemistry: thallus without lichen substances; pigmented parts of apothecia with small amounts of the rubella-orange pigment.
Note: a recently-described epiphytic species, widespread but not common in Tyrrhenian Italy, mostly in shaded-humid situations, with optimum within eu-Mediterranean vegetation. It may, however, prove to be a synonym of Bacidina phacodes (Ekman in litt.).