Nordic J. Bot. 31(1): 38 (2013).

Basionym: Caloplaca arnoldiiconfusa Gaya & Nav.-Ros., in Gaya, Bibliotheca Lichenol. 101: 54 (2009).

Protolog: Data lacking.

Type locality: Austria: Steiermark [Styria]: Bez. Bruck a.d. Mur, Hochschwab-Gruppe: Hochstein (S der Mitteralpe), N Aflenz, 1730-1740 m, Gipfelschrofen, 25.7.1993, leg. J. Poelt (GZU-holotypus).

Barcode: Data lacking.

Coordinates: Data lacking.

Thallus: crustose, epilithic, placodioid, strongly adherent to substratum, forming well-delimited rosettes, 0.5-11 mm in diam., that usually persist, although can merge in some adult specimens, deep reddish-orange to lead red, without pruina in most individuals, K+ (purple). Areoles located in center thallus, polygonal or irregular, relatively flat, 0.4-1 mm in diam., covered by scattered or slightly grouped apothecia. Marginal lobes convex, but occasionally slightly flattened toward tips, highly branched, with several subbranches relatively narrow and deep, contiguous, sometimes imbricate, 0.1-0.9(1.5) mm long and 0.1-0.6(0.9) mm wide at tips. Often areoles and lobe bases suffer necrosis and the central part of the thallus becomes whitish. Thallus in section (85)100-250 µm thick. Upper cortex thin, 15-50 µm thick, with a yellowish-orange external part 7-15 µm thick, and a hyaline inner part 10-35(40) µm thick, scleroplectenchymatous type A, with irregularly arranged hyphae consisting of more or less rounded hyaline cells of lumina 2.5-6.5(10) x 2-5 µm, with scarce amount of superficial crystals visible when examined with polarized light. Algal layer more or less continuous, 25-120(125) µm thick, formed by densely arranged algal cells. Photobiont chlorococcoid, with globose cells 6-26.5 µm in diam. Medulla usually forming a lax net, with hyphae 3-5 µm thick. Apothecia pseudolecanorine, 0.1-0.6(0.8) mm in diam., dispersed or grouped either on the areoles or lobe bases, usually rounded or somewhat distorted by mutual pressure, with a wide or constricted base. Disk flat to convex, orangish-brown to dull red, usually without pruina, K+ (purple), even. Margin lighter than disk, without a clear differentiation between proper and thalline margins, thin, 30-100 µm wide, usually without pruina, even or slightly rugose, more or less persistent and initially emergent but remaining at the same level as disk, proper margin sometimes remaining slightly prominent. Epihymenium 10-14 µm thick, brownish-orange, K+ (purple). Hymenium 40-77.5(82) µm tall, hyaline. Subhymenium and hypothecium hyaline, the latter scleroprosoplectenchymatous. Algal layer beneath hypothecium more or less continuous. Hyphae below algal layer laxly arranged. Parathecium 30-72 µm wide, consisting or radially arranged hyphae, scleroplectenchymatous type A, or occasionally B. Paraphyses septate, sparsely apically or sub apically branched, sometimes bifurcated, 1.5-3(3.5) µm wide at the base and only with the apical cell slightly or highly swollen, (2.5)3-7(8.5) µm wide. Asci 35-62 x 9-15(16.5) µm, claviform, octosporate. Ascospores polarilocular, hyaline, narrow to wide ellipsoid, (8.5)10-11.312.8(15.5) x (3.8)5-5.9-6.5(7.5) µm, with an equatorial thickening ('septum') (2.5)3-3.5-4(4.8) µm, a length/width ratio (1.4)1.6-1.9-2.3(3.1) and a length/equatorial thickening ratio (2.3)2.8-3.2-3.7(4.6). (Gaya 2009: 54-55).

Photobiont: Data lacking.

Chemistry: No lichen substances (Gaya 2009: 54-55).