Ecology: Biotroph; lichenized or lichenicolous; growing on non-calciferous rock. Host or Phorophyte Taxonomy: Dimelaena, Physciacaeae. Thallus: Crustose, areolate (primarily areolate); separate thallus parts thick (up to 1.5 mm). Thallus Outline: Soon disappearing. Upper Surface: Lemon (citrine) (to), matt or slightly glossy (shiny), smooth (to strongly wavy). Medulla: Iodine reaction in Lugol's solution negative. Reproduction Strategy: With sexual (and possible asexual) stages. Ascocarps: Soon sessile, slightly constricted or strongly constricted at the base, up to 1.7 mm in diam.. Margin: Lecideine/biatorine, excluded, distinct or indistinct (0.05 mm). Disk: Plane or strongly convex (when older), black, epruinose. Exciple: Not carbonized; white (partly, if crystals present), dark green, or aeruginose. Parathecium (proper excipulum): White, inspersed with crystals (partly). Amphithecium (thalline excipulum): Present. Epithecium: Apical cells slightly swollen, dark green or turquoise. Hymenium: White. Hypothecium: Pale yellow (if damaged ?) or white. Ascospores: c. 8 per ascus, ellipsoid, 10-13 µm long, 5.5-7.5 µm wide; septa absent; wall thick (not halonate), distinctly differentiated into primary and secondary wall (not halonate), not ornamented (not halonate). Secondary Metabolites: 2,5,7-trichloro-3-O-methylnorlichexanthone (Dichlornorlichexanthone in traces), atranorin, chodatin, demethylchodatin, isoarthothelin (= 2,5,7-trichloronorlichexanthone) (in traces), thiophanic acid (= 2,4,5,7-tetrachloronorlichexanthone), or thuringione (= 2,4,5-trichloro-3-O-methylnorlichexanthone), of the following substance class(es): xanthones. Spot Tests: Upper surface: K – (negative) or + deep yellow, C – or + orange, PD – or + yellow.