Caloplaca caesiorufella  

Thallus: to ca 10 mm diam., mostly immersed in the substratum, the surface white to pale silver grey, sometimes slightly farinose.
Anamorph: not known.
Teleomorph: ascomata apothecia, 200-600 (-800) µm diam., scattered to somewhat crowded, sessile, disc flat to slightly concave, red-brown, sometimes faintly granular but not pruinose. Margin concolorous to slightly paler than the disc, initially prominent but usually eventually becoming excluded, rarely flexuous. Excipulum 25-50 μm wide, with few or no algal cells; the inner part narrow and poorly developed, composed of interwoven hyphae in a gelatinous matrix, the outer part pale brownish. Hypothecium hyaline, containing oil droplets. Subhymenium hyaline. Hymenium to 60 μm high, hyaline or with a diffuse reddish to brownish coloration in the upperpart. Interascal tissue of branched and sometimes gelatinized paraphyses, terminal cells simple or swollen, 2-5.5 μm diam., hyaline or eventually conglutinated and coloured reddish brown. Epithecium K+ purple. Asci 50-55 × 15 μm, clavate, usually 8-spored. Ascospores 9.5-13 × 5-5.5 μm, ellipsoidal, 1-septate, the septum median and 3-4.5 μm thick, hyaline, smooth, without a gelatinous sheath or appendages.
Chemistry: thallus K–, apothecia K+ purple.

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