Lichenogr. Universalis: 626 (1810).

TYPE: Germany, Lausitz region (Lusatia), Mosig (H-ACH 1893 holotype). Syn. Dolichousnea longissima (Ach.) Articus Thallus pendent, to 3 m long, draping horizontal branches; sparsely branching 2 of the filamentose type with strongly parallel, ? isodiametric branches. Basal part dif?cult to localize and see because the thallus become detached and drape over the tree branches, often with several attachment points present. Main branches cylindrical, with cortex scaling off, leaving a rough, dull, whitish, ecorticate surface; almost undivided, with many perpendicular secondary branches resembling long ?brils, not narrowed at their point of attaclnnent to the main stems. Segments cylindrical and terete to distinctly ?attened. Papillae absent or few, verrucose. Tuberucles and ?bercules absent. Fibrils absent or few, spinulous, 2-3 mm long. Soralia occasional, punctifonm, smaller or as large as half the branch, arising ad initio on the cortex of lateral branches; isidiomorphs few to absent. Cortex of main branches soon disintegrating leaving rough patches of white medulla, thin when present (2-3.5%); medulla thin (6—12%), compact, whitish; axis thick (69-86%), whitish, pinkish to brown; A/M = 4-15. Apothecia rare, lateral on lateral branches. Pycnidia not observed. Chemistry: Medulla C-, K-, KC—, PD-; diffractaic, ? squamatic acids, ? unknown fatty acid (A2/B3) or evernic acid. Habitat: Usually on Picea in old-growth forests in boreal and montane areas. Distribution: From the surroundings of Oslo to the coast of central Sweden with the northernmost known localities in Nordland and in Norrbotten and a few scattered localities in eastern Finland. Sems to occur only in the Northern Hemisphere where it is circumpolar, although absent or extinct in large areas. In Europe and Asia it grows in areas with high atmospheric humidity but it seems to be more oceanic in North America. --> Basionym:

Synonym: Index Fungorum

Type: Germany, Saxonia, Lausitz region ("Lusatia"), Mosig (H-ACH 1893 – holotype).