Lecania cyrtellina (Nyl.) Sandst.
Thallus crustose, thin and continuous, smooth to slightly verrucose and cracked, very pale grey, dull whitish, pale grey-greenish. Apothecia usually numerous, sometimes clustered and tightly packed, sessile, 0.1-0.3 mm diam., disc flat soon convex, translucent and dotted with brown when moist, pale brown-orange, brown-pink, exciple thin, dull whitish to pale brownish. Asci 8-spored. Ascospores fili-fusiform, usually not septate (but seldom 1-3-septate unless it corresponds to macronidia?), 9-11 x 2-2,5 µm. Micronidia 14-16 x 0,5 µm, curved, macronidia 10-15 x 1,5-2 µm, crescent-shaped, 0-1-septate. Chemical spot tests negative. Rare, on shaded alkaline bark of deciduous trees, apart from the Xanthorion species. See Lecania cyrtella more common and associated to the Xanthorion species and of which apothecia are larger, darker with larger ascopsores, 1-septate. See also Lecania naegelii of which the thallus is thicker and ascospores 3-septate.*