Arthonia ilicina T. Taylor

   Thallus thin, more or less immersed in bark, white to cream-pink to cream-yellow, ± apparently stained by transparency due to the colour of bark below, in general well delimited by a brown, large and clearly visible prothallus. Apothecia numerous, irregularly rounded, scattered or in small clusters, 0,2-0,5 x 1-1,5 mm in diam., red-brown to brown chocolate, dark brown, to deep dark-brown. Ascospores ovoid-oblong, often slightly curved, smooth and colourless, and when old, brown and very faintly warted, 4- to 6-septate, the upper cells enlarged,  25-36 x 10-13 µm. Photobiont : Trentepohlia. Chemical spot tests negative. Species showing  oceanic trends, common on bark of deciduous trees in old woodlandsand especially on holly (Ulex).*