Aspicilia intermutans (Nyl.) Arnold

    Thallus crustose, areolate; areoles irregular, verrucose, pale grey more or less green or brown tinge, dark grey, grey-brown, seldom dark grey or grey-brownish; black prothallus. Apothecia 2-3 per areole, initially immersed, then sessile, rounded, 0,5-1,2 mm diam., disc concave, seldom pruinose, matt black, exciple thick. Asci with 8 spores, club-shaped, 140-160 x 35-40 µm according to our measurements. Spores broadly elliptical to ovoid, simple, 22-28 x 11-14 µm according to literature, 21-29 x 14-18 according to our measurements.  Conidiospores (pycnidiospores) 7-12 x 1 µm. Photobiont: Chlorococcales. K+ yellow > dark red, Pd+ orange. Rare, maritime trend on top or walls of slightly acid flat and lower rocks. Not especially maritime, difficult to discriminate without microscopic observation from close species, maritime or not, since characteristics analysed by different authors significantly differ, see also Aspicilia grisea ss. str., Aspicilia epiglypta and Aspicilia cupreogrisea (possibly conspecific?), Aspicilia cupreoglauca. Because of this confusion in the interpretation of the species of this group and in the expectation (perhaps utopian) of a clarification we give here, with the usual reservations, our own interpretation and Netherland and British interpretation.