Rhizocarpon lunulatum Zahlbr.
Holotype: New Zealand. Otago, head of Verter Burn. J.S. Thomson 127 pr.p., W - not seen.
Thallus rather small, greyish to brownish-grey to blackish, areolate, prothallus black, thin, spreading. Areolae minute, 0.1-0.2 mm diam., rounded or angular, somewhat congested, dispersed on prothallus, flat to subconvex, separated by wide to narrow cracks. Apothecia sessile, black, epruinose, rounded, constricted at base, scattered, minute, between areolae, to 0.3 mm diam., concave or plane, margins thin, entire, persistent. Hymenium blackish, K+ purple to colourless, 150-170 µm tall. Paraphyses filiform, branched, apices rounded. Asci ellipsoid-clavate, apices rounded, walls thick, subpedicellate, 8-spored. Hypothecium thick, brown-black. Ascospores biseriate, colourless at first, becoming brownish, oval to oval-oblong, apices rounded, ± curved, semilunar, 3-7-septate, becoming muriform, 26-30 × 9-12 µm.
S: Otago. On subalpine rocks. Known only from the type collection.
Endemic
