Thallus thick, white, areolate-cracked, margins zonate, determinate, cracking radially, prothallus narrow to wide, black. Areolae to 1 mm diam., sometimes sorediate. Soralia to 0.5 mm diam., leaving white pits. Apothecia innate, disc black 0.1-0.2 mm diam. Hymenium 160 µm tall. Paraphyses slender, flexuous, branched and anastomosing, repeatedly branching above asci, apices moniliform, dark brown. Asci cylindrical 125-130 × 35 µm, 8-spored. Ascospores uniseriate, broad, ellipsoid 25-50 × 15-18 µm colourless at first becoming brownish with age, muriform.