Lichenogr. Univ.: 595, 1810. Basionym: Lichen sarmentosus Ach. in Liljeblad - Utkast Svensk Flora: 427, 1792.
Synonyms: Alectoria cincinnata (Fr.) Lynge; Alectoria luteola Mont. ex De Not.; Alectoria sarmentosa var. cincinnata (Fr.) Nyl.; Alectoria sarmentosa var. genuina Flagey; Alectoria sarmentosa var. sorediosa (K.G.W. Lång ex Räsänen) Du Rietz; Alectoria sarmentosa var. tortilis Sambo
Description: Thallus fruticose, filamentous, pendent, flaccid except at base, 20-40(-80) cm long, attached by a basal holdfast, branching mainly isotomic-dichotomously; branches terete, often becoming compressed and angular-foveolate towards the base and at axils, 0.5-2.0(-2.5) mm thick, greenish grey to yellowish green; pseudocyphellae white, abundant, conspicuous, raised, elongate-fusiform to tuberculate, clearly delimited, usually c. 1 mm long. Apothecia rare, lecanorine, mostly lateral. Asci 2-3(-4)-spored, clavate-ovoid, Lecanora-type. Ascospores 1-celled, hyaline but finally often brownish, ellipsoid, 23-40(-48) x 12-25 µm. Pycnidia mainly apical, up to c. 2 mm diam., black, shining. Photobiont chlorococcoid. Spot tests: cortex K-, C-, KC+ pale yellow, P-, UV-; medulla K-, C-, KC+ red or KC-, P-, UV+ ice-blue. Chemistry: cortex with usnic acid; medulla usually with alectoronic acid (major), squamatic and a-collatolic acids (all accessory).
Note: a cool-temperate to boreal-montane, probably circumpolar species found on branches, more rarely on trunks of (mainly) conifers in forests with frequent fog, with optimum in the montane belt. More common in the past, it is presently confined to upland areas and is certainly declining, being very sensitive to air pollution and forest management. The species is included in the Italian red list of epiphytic lichens as “Near-threatened” (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)