Description: Thallus fruticose, filamentous, attached by a basal holdfast, long-pendent, soft, to 30 cm long, whitish grey to to brownish grey, very rarely dark brown in sun-exposed morphs, usually without a main branch, irregularly branching with acute angles, the branches terete to flattened at axils, to 0.5 mm thick. Soralia absent to usually abundant, small, tuberculate, with farinose soredia. Pseudocyphellae sparse, fusiform, usually inconspicuous; medulla white, compact. Apothecia extremely rare (never observed in Italian material), zeorine, with a brown disc, to 1-2 mm across. Asci 8-spored, Lecanora-type. Ascospores 1-celled, hyaline, subglobose to ellipsoid, 5-9 x 4-6 μm. Photobiont chlorococcoid. Spot tests: cortex and medulla K+ yellow, C+ red or C-, KC+red, P+ yellow; soralia P+ red; apothecia P+ yellow. Chemistry: barbatolic acid, sometimes alectorialic acid and atranorin in cortex; fumarprotocetraric acid in soralia; psoromic acid in apothecia.
Note: a temperate to boreal-montane, circumpolar lichen, with optimum in montane humid Fagus-Abies forests, mostly on twigs, but also on boles of isolated trees in areas with frequent fog. The study of Boluda et al. (2019) revealed a strong mismatch between phenotypes and genotypes in Bryoria sect. Implexae, which brought to the reduction from 11 to 4 species. All European species (B. capillaris, B. chalybeiformis, B. implexa, B. lanestris, B. kuemmerleana, and B. subcana) should be considered as synonyms of B. fuscescens. Due to their chemical and morphological differences, I still provisionally maintain these taxa as separate species, although they should be best treated as chemical races or forms of B fuscescens.
Growth form: Fruticose filamentous
Photobiont: green algae other than Trentepohlia
Reproductive strategy: mainly asexual, by soredia, or soredia-like structures (e.g. blastidia)
Most common in areas with a humid-warm climate (e.g. most of Tyrrenian Italy)