Magnusson, AH. 1939. Studies on Species of Lecanora, Mainly the Aspicilia gibbosa Group. Kongl. Svenska Vetenskapsakad. Handl. 17: 34-35.
Thallus probably covering large areas, uniform, pale ashy-gray with a bluish shade, subfarinose, rimose-areolate, areolae 0.7-1(1.5) mm large. 0.2-0.4(0.5) mm thick, plane, angulose, separated by narrow cracks with perpendicular sides, KOH-, partly slightly ochraceous round the cracks or at the base (Fig. 26).—Cortex 25-35 µ thick, quite gray, upper 4-6 µ dark, +/- brown, amorphous stratum 15-20 µ; in HCl transparent with dark olive surface, cells rather indistinct, 2-3 µ, thick-walled, in +/- perpendicular rows. Gonidia 8-12 µ, stratum 45-65 µ. Medulla partly opaque also in HCl, +/- ochraceous, hyphose, +/- lax, hyphae +/- perpendicular, constrictedly septate with +/- globose cells, partly containing oil.
Fertile areolae larger, sometimes slightly prominent with on the whole plane surface, discs rarely solitary or 2-3, generally 5-15, black, slightly impressed, 0.1-0.2(0.3) mm large, often irregular and +/- confluent.—Apothecia 120-150(200) µ deep. Exciple partly indistinct in water, partly +/- distinct, 10-15 µ thick and I+ blue at the base and laterally. Hypothecium 35-50 µ, cloudy. Hymenium 110-120 µ high, I+ bluish-green to brownish green; upper 15-20 µ olive, in KOH intensely yellow like the surface of the exciple and the parts between two contiguous apothecia. Paraphyses discrete in KOH, apices 2-2.5 µ with +/- short, only constricted articles, brownish. Spores in HCl 17-20(25) X 9-13(14) µ, acc. To B. DE LESDAIN 21-27 X 13-15 µ.
Pycnidia and conidia unknown.
Habitat. On calcareous rock.
Distribtuion. Italy. Piemonte: Valpelline 1912 Abbe HENEY (hb. LESD.) at 2800 m, “sur des roches siliceuses,” but in reality HCl+. “Italy septr. GAROVAGLIO” (U.).
f. chiodectonoides
Thallus becoming violet-chalky, subfarinose, not or somewhat rimose. Apothecial verrucae prominent, margin obtuse.
Thallus indistinctly limited, without hypothallus, towards the centre 0.3-0.4 mm thick. Fertile verrucae dense towards the centre, De 50-90, separated by +/- distinct cracks, generally with 3-10 impressed, +/- confluent discs upon the flattened top which is 0.5-1.5 mm broad, discs 0.2-0.5 mm diam, often irregular in shape, partly umbonate, apparently slightly pruinose.—Cortex 50-60 µ thick with intricate hyphae and indistinct cells. Spores K+ 20-24 X 13-15 µ. Structure well agreeing with that of the type.
Italy. Lombaridai: Ortler, monte Zebru (Kongisspitze) near the glacier, according to ANZI (loc. cit.) Specimen in (U.) without locality.—Novaya Zemlya. Matotchkin Shar, Mt Lasareff 1921 LYNGE (O.), called L. heteroplaca v. homomorpha by ZAHLBRUCKNER. Stone HCl-.
Differs in the violet tone of its thallus surface and the prominent apothecial verrucae.