Distribution: N - Frl, TAA (Obermayer 2003, Bilovitz & al. 2014b), Lomb, Piem (LD-1060365), VA (Piervittori & Isocrono 1999). C - Abr (Nimis & Tretiach 1999, Di Nuzzo & al. 2021, Gheza & al. 2021, Vallese & al. 2022, Lich. Ital. Exs. 61: Isocrono & al. 2022).
Description: Thallus fruticose, greenish to yellowish green, sometimes turning brown in sun-forms, sparsely isotomic-dichotomously branching from near the base, forming tufts. Branches soft, slightly foveolate, ascending to erect, rarely prostrate in forms of wind-swept ridges, subterete or slightly irregular, up to 4 cm tall, 1-2 mm thick. Cortex paraplectenchymatous; medulla white, lax, arachnoid throughout. Apothecia extremely rare (not seen in Italian material), zeorine, subterminal, with a pale brown disc. Asci 8-spored, narrowly clavate, Lecanora-type. Ascospores 1-celled, thick-walled, broadly ellipsoid to subglobose, 6-10 x 4-8 µm. Pycnidia dark, immersed to slightly projecting. Conidia filiform, slightly curved, 13-20 x 0.5-1 µm. Photobiont chlorococcoid. Spot tests: cortex K-, C-, KC+ yellowish, P-; medulla K-, C-, KC-, P-. Chemistry: cortex with usnic acid; medulla with lichesterinic acid.
Note: an arctic-alpine species found in open grasslands and in wind-exposed ridges above treeline, in areas with calciferous substrata; probably widespread throughout the Italian Alps. The record from Abruzzo (central Apennines) is the southernmost one in Europe.
Growth form: Fruticose
Substrata: soil, terricolous mosses, and plant debris
Photobiont: green algae other than Trentepohlia
Reproductive strategy: mainly asexual, by thallus fragmentation