Buellia macularis Zahlbr.
Lectotype: New Zealand. Otago, Hyde, Central Otago. At 400 m on quartz. J.S. Thomson A41 (T2328), CHR 374335!
Thallus pale greyish or yellowish or sordid grey-brown, smooth, matt, areolate-cracked, areolae rounded or angular, widely dispersed, 3-4 mm diam., becoming confluent, roughened in parts, prothallus black, stellate-fimbriate, radiating 0.5-2 mm wide, in irregular patches 0.3-1.5 cm diam., saxicolous. Apothecia clustered, innate ± sessile, solitary to 1-3-confluent, flat, 0.1-1.0 mm diam., disc black, matt, epruinose, often obscuring areolae, margin thin, black, entire, persistent. Hymenium brown-black above, colourless below, 110-115 µm tall. Hypothecium thick, colourless. Ascospores biseriate ellipsoid to ovoid, apices round or pointed, straight or slightly curved and ± fabiform, slightly constricted at septum 12-16 × 6-6.4 µm.
S: Otago (Hyde, Stoneburn). On quartz rocks and pebbles.
Endemic
B. macularis appears to be restricted to quartz, and is characterised by the very closely attached thallus almost immersed in the quartz, and the fine, black, stellate, marginal prothallus, reminiscent of Cystocoleus.
