Distribution: C - Sar (Zedda 2002). S - Pugl (Thüs & Licht 2006).
Description: Thallus fruticose-filamentous, greenish, shrubby to subpendulous, branching mainly isotomic-dichotomously with divergent branches, 4-8(-15) cm long. Main branches cylindrical, 0.7-1.3 mm thick, often foveolate or with transversal cracks especially toward the base, which is black for several mm, the blackening sometimes extending to the lower lateral branches. Lateral branches constricted at attachment point. Papillae sparse to numerous, most frequent on the main branches; tubercles absent; fibrils rare to numerous, 3-6-(-10) mm long. Soralia irregularly orbicular to transversely elliptical, well delimited, plane to stipitate, occupying more than half the diameter of the branch, originating from cortex, rarely confluent and covering the entire branch; isidiomorphs numerous only in young soralia, absent in old ones, 0.1-0.2 mm long. Cortex matt in longitudinal section, very thick (10-19% of total thickness); medulla homogeneous, very compact, thin (7-13%), white; central axis white, thick (47-63%). Apothecia not observed in Italian material. Photobiont chlorococcoid. Spot tests: cortex K-, C- KC-, P; medulla K+ yellow to red, C-, KC-, P+ yellow-orange. Chemistry: usnic acid in cortex; medulla with salazinic (main) and consalazinic acids.
Note: a mainly western species of humid montane forests. It is included in the Italian red list of epiphytic lichens as “Endangered” (Nascimbene & al. 2013c).
Growth form: Fruticose filamentous
Photobiont: green algae other than Trentepohlia
Reproductive strategy: mainly asexual, by thallus fragmentation
Most common in areas with a humid-warm climate (e.g. most of Tyrrenian Italy)