Mém. Soc. Phys. Hist. Nat. Genève 16, 2: 376 (1862).
Basionym: Lecidea triptophylla Ach., K. Vetensk-Acad. Nya Handl. 29: 272 (1808).
Thallus: Hypothallus well developed, blue-green to blue-black, extending beyond the thallus 1-1.5 mm; thallus squamulose, the squamules apparent at the thallus margins; the lobes to 1.5 mm long and 0.5 mm broad, the tips rounded; centrally the ridges and lamina isidiate with cylindrical, branched isidia 0.04-0.12 mm thick, commencing as papillae on the upper surface and eventually covering the center of the thallus; upper surface cherry red to brown, blue-black when wet, dull, epruinose, esorediate; underside black or blue-black and with fine black or blue-black tomentum; upper cortex hyaline or yellowish brown, paraplectenchymatous, 22.5-30.5 µm thick, algae glomerate in the algal layer, lower cortex lacking. Apothecia adnate, round, with proper exciple; thalloid exciple lacking; margin narrow, entire, dull, of the same color as the disk or paler; disk rust red, smooth, epruinose; epithecium hyaline or reddish; hymenium hyaline, 70-100 µm; asci with compact plug-like apical apparatus; paraphyses hyaline, 2 µm thick; spores ellipsoid, one end more pointed than the other, 13-17 x 5-7.5 µm (Thomson 1984: 321).
Photobiont: Data lacking.
Chemistry: Hymenium I+ blue, other reactions all -. Contents unknown, Dey (Bryologist 81: 1-93, 1978) records traces of atranorin (Thomson 1984: 322).
Ecology: On mosses and soil in the arctic but mainly on trees further south. Apparently seldom collected in North America (Thomson 1984: 322).
Distribution type: Circumpolar, temperate to subalpine or arctic (Thomson 1984: 322). South Carolina, Louisiana, Australia, New Zealand.
Taxonomy: Data lacking.
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