Distribution: N - Ven (Lazzarin 2000), Lomb (S- F145122), Piem (Isocrono & al. 2004). C - Tosc.
Description: Thallus squamulose to subfoliose, 3-8(-10) mm wide, umbilicate-monophyllous, firmly attached, homoiomerous, gelatinous when wet, black, sometimes grey-pruinose in central part, with a central depression and down-turned margins, attached by a central holdfast. Apothecia rather rare, laminal, immersed, with an initially pore-like, then slightly expanded and urceolate disc and a thick thalline margin. Proper exciple very thin, of parallel hyphae; epithecium brownish; hymenium and hypothecium colourless, K/I+ blue; paraphyses mostly simple, coherent, not apically thickened; hypothecium colourless. Asci 8-spored, prototunicate, cylindrical, without a distinct apical apparatus. Ascospores 1-celled, hyaline, narrowly ellipsoid to fusiform, 15-27 x 7-10 μm. Photobiont cyanobacterial (Nostoc, in chains). Spot tests: K-, C-, KC-, P-, UV-. Chemistry: without lichen substances.
Note: a mainly temperate lichen found on steeply inclined faces of calcareous rocks, in seepage tracks, often with other cyanobacterial lichens, certainly much overlooked throughout Italy.