Buellia dunedina Zahlbr.
Lectotype: New Zealand. Otago, Horse Ra. near Dunback. J.S. Thomson 2309 (T1426), CHR 379350!
Thallus spreading, in patches 1-5 cm diam., or more, often flaking or eroding from substrate, 0.015-0.12 mm thick, roughened in parts, pale yellowish-grey or rarely yellowish-olive, matt, areolate, areolae 0.5-1.0 mm diam., angular, flat, separated by narrow cracks, in central parts convex-verrucose, black prothallus visible between areolae and at margins, saxicolous. Apothecia frequent, scattered to 3-4-confluent rounded or contorted through mutual pressure, plane at first becoming distinctly convex, 0.5-1.2 mm diam., black, matt, roughened-scabrid or minutely cracked, epruinose, margins thin, entire, persistent, concolorous with disc. Epithecium brown-black, 30-36 µm thick. Hymenium 90-95 µm tall, colourless. Hypothecium carbonaceous. Paraphyses filiform, dense, straight, felted, apices swollen, 3 µm diam. Ascospores biseriate oval-ellipsoid to fabiform, slightly constricted at septum, apices rounded, 15.3-20.4 × 8.3-9 µm.
S: Otago (Horse Ra., Macraes Hill).
Endemic
