Description: Thallus crustose, endosubstratic or thinly episubstratic but poorly evident and reduced to small granules around the apothecia, pale yellow to yellowish brown, sometimes with a distinct prothallus of whitish dendroid hyphae. Apothecia lecanorine, sessile, 0.3-0.8(-1) mm across, with a flat to slightly convex, pale brown to reddish brown, epruinose or slightly pruinose disc, and a thin, smooth, entire thalline margin. Thalline exciple c. 60 μm wide, more or less distinctly corticate, the cortex inspersed with sparse crystals visible under polarized light, which are insoluble in K and soluble in N; epithecium yellow-brown to reddish brown, K- and N-, inspersed with coarse crystals visible under polarized light, which are soluble in K and insoluble in N, overlain with an epipsamma of very small crystals insoluble in K and soluble in N; hymenium colourless, 50-70 μm high; paraphyses simple or sparingly branched in upper part, 1.5-2 μm thick at base, the apical cells slightly swollen; hypothecium colourless to yellowish 100-120 μm high, of adglutinated hyphae, without crystals. Asci 8-spored, clavate, very thin-walled, with a K/I+ blue, tall tholus penetrated by a faintly amyloid apical cushion, the wall K/I-, surrounded by a blue outer layer, Lecanora-type. Ascospores 1-celled, hyaline, ellipsoid, 9-15 x 4.5-6 μm. Photobiont chlorococcoid. Spot tests: thallus and apothecial margin K+ pale yellow, C+ orange, KC+ orange, P- or P+ orange; apothecial disc K+ yellow, C+ orange, KC+ orange, P+ orange; apothecia UV+ yellowish to yellow-orange. Chemistry: an unknown xanthone, plus variable quantities of pannarin.
Note: a maritime silicicolous lichen, probably restricted to Tyrrhenian Italy. For further details see Bertrand & Roux (2011).
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)