: Ecology: Biotroph; lichenized; endosubstratic or episubstratic; substrate non-calciferous or metalliferous. Thallus: Areolate (primarily areolate), continuous throughout, dispersed along the periphery, continuous in the centre, or dispersed throughout and distinctly seperate; lobes angular or rounded at the front; separate thallus parts 0-1 mm thick. Thallus Size and Differentiation: Large; main branches basally not constricted. Thallus Outline: Margin concolorous the thallus centre. Upper Surface: White, lemon (citrine), brownish yellow, pale grey, or green (olivaceous), convoluted, plane or convex; not sorediate; without thalloconidia thalloconidia. Medulla: Iodine reaction in Lugol's solution negative. Ascocarps: Forming rarely on the pro- or hypothallus, soon sessile, slightly constricted or strongly constricted at the base, 25-200 per cm², .6-1.5-(2) mm in diam.. Margin: Not flexuose or slightly flexuose, persistent or excluded, 35-170 µm wide, epruinose. Disk: Plane, weakly convex, or strongly convex, black, epruinose, without an umbo. Exciple: Hyphae radiating outwards; 3-5 µm wide; grey; inspersed with crystals. Epithecium: Apical cells olive, green, or rarely black, cell pigment reacting with 10% HCl (in H2O). Hymenium: 35-59 µm high; white; iodine reaction: Lugol’s positive. Subhymenium: 30-86 µm high; white. Hypothecium: White, brownish yellow, or brown. Ascospores: Oblong, (7)-7.9-14.8-(16) µm long, (3)-3.5-5-(6.5) µm wide; wall not ornamented. Conidia: (11)-12.5-15-(17) µm long. Secondary Metabolites: Rarely not detected or present, planaic acid or 4-O-demethylplanaic acid. Spot Tests: Medulla: K –, C –, PD – ascocarp margin (in section): K –, C – disk: C – hypothecium: K – epihymenium: K –.