Rinodina confragosa (Ach.) Körb.
Thallus crustose, more or less thick, rimose, flat, presence of understated warts with slightly indented margins, pale grey, whitish cream, prothallus inconspicuous. Apothecia, 0.6-1.5 mm diam., sessile, often crowded together, disc flat becoming convex, black, exciple persitent, erect (up to 0.1 mm tall), concolourous to thallus, little or not crenulate. Ascospores broadly ellipsoid, thick walls, 1-septate with angular locules, 17-27 x 8-13 µm. Photobiont: Trebouxia. Thallus : K+ yellow, Pd+ yellow. Strong maritime trends, on coastal siliceous rocks. Sometimes together with Lecanora gangaleoides and Tephromela atra that makes the identification difficult on the field. Some morphotypes of Rinodina beccariana cannot be distinguished unless an ascospores observation is done.