Enterographa zonata (Körber) Torrente & Egea

    Thallus crustose, more or less thick, minutely warted or cracked, brownish, brown-chocolate, brown-purple, quite often grey-brown when immature and fresh, with pale lilac or violet tinge, prothallus black, conspicuous in case of mosaics, covered with abundant punctiform isolated soralia, 0.5-1 mm diam., pale brown, brown-violet, lilac.. much paler when eroded or old and then contrasting with the dark thallus. Apothecia rare, only in places devoid of soralia, rounded or lirelliform, open from below, 0.2-0.4 x 0.1-0.3 mm  long, black, not divided and unbranched, disc at the bottom of a slot, black. Ascospores fusiform, pointed at apices, 6-7-septate, 24-28 x 4-6 µm. Chemical spot tests negative. Rather rare, on damp shaded rocks, old damp and shaded walls, very rare on the bark of trees in humid forests, see: Enterographa zonata forme corticole.

_ Most often in combination within mosaics with Gyrographa (Opegrapha) gyrocarpa  that is brown-orange or yellow-lemon and of which the soralia are less delimited and C+ red.

N.B. An extraordinarily variable species with forms with virtually no clearly visible thallus except for its purplish margin, covered only with globose soralia of creamy coloration with lilac highlights, and forms with a thick, purplish-grey thallus with numerous lirelliform apothecia  and no soralia, with all possible intermediates between these two extreme forms.