Distribution: N - Lig (Ravera 2006b). C - Tosc (Ravera 2006b).
Description: Thallus crustose, endosubstratic, poorly evident, probably not lichenized. Perithecia black, scattered, 0.1-0.3 mm in diam., subglobose, circular or ellipsoid in outline, often with depressed ostioles. Involucrellum dimidiate, dark brown, K-, 13-20 μm thick, intermixed with c. 22.214.171.124 μm thick, dark hyphae, the amorphous pigment localized in the cell wall; exciple brown in upper part, colourless at base, 5-7 μm thick, K-; pseudoparaphyses dissolving and leaving only fragments (to 1 μm wide) embedded in gel; periphysoids 5-15 x 1-2 μm, branched and septate. Asci 8-spored, obclavate-obpyriform, fissitunicate, the endotunica thickened to the apex, with a rounded ocular chamber, the obconical structure in tholus I+ blue. Ascospores 1-septate, hyaline, 8.8-10.9 x 3-4.5 μm, non-guttulate, constricted at septum, with a larger upper cell and a pointed lower cell; perispore indistinct but immature spores from broken asci have a broad halo. Photobiont probably absent. Spot tests: all negative. Chemistry: without lichen substances.
Note: a recently-described, probably non-lichenised species, apparently related to A. salicis, with which, according to Ravera (2006b) it was confused by Putortì & Loppi (1999) and Brunialti & al. (2001). It occurs on rough bark, especially of Fraxinus excelsior, in species-rich communities of well-preserved deciduous woodlands.
Growth form: Fungus
Reproductive strategy: mainly sexual
Most common in areas with a humid-warm climate (e.g. most of Tyrrenian Italy)