in Frisch & al., MycoKeys, 62: 41, 2020.. Basionym: Arthonia cinnabarina f. cuspidans Nyl. - Flora, Regensburg, 59: 310, 1876.
Description: Thallus crustose, endosubstratic or thinly episubstratic, sometimes evanescent, dirty orange, ochraceous or whitish, sometimes delimited by an orange-violet prothallus. Apothecia arthonioid, very variable in shape, from ellipsoid to weakly lirelliform, often confluent into stellate groups, 0.2-0.6 x 0.1-0.2 mm, with a reddish brown to brown-black, sometimes thinly white-pruinose, lacking an orange-red-pruina. Proper exciple poorly developed, brown, 7–20 μm wide; epithecium yellowish brown, 10-20 μm high, K+ purple; hymenium colourless to yellowish red, 40-50 μm high, K-, J+ blue; paraphysoids 1-2 μm thick, conglutinated only in lower parts, the branched tips 3(-4) μm wide, extending horizontally above the asci; hypothecium poorly developed, 10-25 µm high, colourless to pale yellowish brown. Asci 8-spored, broadly clavate to subglobose, semi-fissitunicate, with a large apical dome and a distinct ocular chamber, Arthonia-type, without K/I+ blue tholus structures. Ascospores (2-)3(-4)-septate, hyaline turning pale brown-when overmature, oblong-ovoid, with a larger cell at one apex, (15-)16-18(-20) x (6-)7-8(-9) μm. Photobiont trentepohlioid. Spot tests: thallus K-, C-, KC-, P-. Chemistry: thallus without lichen substances; anthraquinones in epithecium.
Note: similar to C. fallax, but apothecia epruinose and ascospores slightly smaller. Never reported from Italy, but probably previously identified as C. fallax.