Synonyms: Bacidia arbuti (Bagl.) Jatta; Pachyphiale arbuti (Bagl.) Arnold
Distribution: N - Lig. C - Tosc (Loppi & al. 2004b), Sar.
Description: Thallus crustose, thinly episubstratic, whitish, somehow glossy, sometimes poorly evident. Apothecia 0.3-0.6 mm across, usually numerous, urceolate, gelatinous and translucent when wet, with a concave, orange or reddish brown to finally dark brown disc, and a darker, thick, raised, smooth proper margin. Proper exciple well-developed, of narrow, thin, compacted hyphae, reddish brown in outer part, pale within; epithecium reddish brown; hymenium colourless; paraphyses simple, septate, more or less hooked at tips; hypothecium colourless. Asci 16-48-spored, thin-walled, lacking an apical apparatus or tholus, K/I+ blue. Ascospores transversely 6-12-septate, hyaline, acicular, straight to slightly curved, (26-)32-46(-52) x 3-4.5 µm, with apiculate ends. Photobiont trentepohlioid. Spot tests: K-, C-, KC-, P-. Chemistry: no lichen substances.
Note: a species of Mediterranean, rather humid forests, frequently confused with G. carneola. It is included in the Italian red list of epiphytic lichens as “Data Deficient” (Nascimbene & al. 2013c).
Growth form: Crustose
Reproductive strategy: mainly sexual
Most common in areas with a humid-warm climate (e.g. most of Tyrrenian Italy)