Lecanographa lyncea (Sm.) Egea & Torrente
Arthonia lyncea (Sm.) Ach.
Lecanactis lyncea (Sm.) Fr.
Thallus crustose, rather thick, smooth or with slightly granulose sections, sometimes cracked, white, whitish. Apothecia very abundant and scattered all over the thallus, at first more or less immersed, then hardly emerging to the surface, highly variable, rounded, elliptical, lirelliform (short and wide), sometimes dual footprint-like in snow, 0.3-1 x 0.3-0.5 mm, disc flat, black when rain-washed but usually pale grey-bluish or greyish, seldom grey-brownish, in that case owing to dense whitish pruine, exciple hardly prominent, inconspicuous, wavy, excluded when mature. Ascii clavate, 8-spored, 80-110 x 20-25 µm according to our measures. Ascospores hyaline at first, then, brown when mature, fili-fusiform, straight or slightly curved, 6-7-8-(10)-septate, slightly constricted towards septa when mature, perispore colourless, 23-35 x 3-4 µm according to literature, 25-35 (40) x 6-9 µm according to our measures. Photobiont: Trentepohlia. C-, K-, KC-, Pd-. Rare, strong maritime trends, on dry barks at the base of old isolated tree trunks (Quercus), notably inside chapel enclosures. See Arthonia pruinata which, at the naked eyes, is rather similar and may grow nearby, but with more distorted, less blackish and more brownish apothecia, smaller and less septated ascospores, and C+ red, KC+ red.