J. Hattori Bot. Lab., 76: 205, 1994. Basionym: Pannaria leucosticta Tuck. - Ann. Sci. Nat., Bot., 12: 294 1859.
Synonyms: Pannaria craspedia Körb.
Distribution: N - VG, Frl (UPS-L-168860), Ven, Lomb, Piem, Lig (Watson 2014). C - Tosc, Sar (Zedda 2002).
Description: Thallus small-foliose to squamulose, heteromerous, usually 3-5 cm diam., developing on a black hypothallus. Squamules rounded, to 2-3 mm wide, the marginal ones often elongated and up to 3-4 mm long. Upper surface brown to chestnut brown, sometimes paler, with white-felted tomentose margins. Upper cortex paraplectenchymatous, 40-50 µm thick, of thick-walled cells. Apothecia common, up to 1.5 mm across, with a brown, flat disc and a white-felted thalline margin. Exciple subparaplectenchymatous, 20-30 µm thick; hymenium colourless c. 100 µm high, I+ blue-green rapidly turning red-brown; paraphyses simple, coherent, slightly swollen at apex; hypothecium colourless. Asci 8-spored, clavate to subcylindrical, with a I+ blue tholus and an internal, more intensely I+ blue structure. Ascospores 1-celled, hyaline, ellipsoid, with a conspicuous epispore which is acuminate at both apices, 14-18 x 8-9 µm, including the epispore 23-27 x 9-11 µm. Pycnidia wart-like. Conidia bacilliform. Photobiont: cyanobacterial (Nostoc in short chains) Spot tests: thallus K-, C-, KC-, P-, UV-. Chemistry: terpenoids and aliphatic acids.
Note: on mossy trunks of broad-leaved trees; there are no recent records from the Alps of this declining species, which is included as “Regionally Exctinct” in the Italian red list of epiphytic lichens (Nascimbene & al. 2013c).