Pertusaria nothofagi Zahlbr.
Lectotype: New Zealand. Otago, Silver Peaks near Dunedin April 1934. On Nothofagus menziesii. J.S. Thomson ZA 281, W!
Thallus in patches or bands, 3-8(-20) cm diam., pale olivaceous-grey to grey-white, matt or shining, irregularly wrinkled-plicate or ridged, irregularly cracked to ± areolate. Apothecia sessile, constricted at base 0.5-2.5 mm diam., ± hemispherical at maturity, blister-like at first becoming erose-white-sorediate, disc subconcave to plane, often fissured, pale buff to dark brown or grey, densely white-pruinose, pruina granular, margins thick, fissured, eroding, roughened-granular, Geaster -like, covered with thallus at first then white-sorediate. Asci clavate, with well-developed apical tholus, 8-spored (rarely 6-spored). Ascospores uniseriate, oval-ellipsoid, pointed at one end, rounded at other, occasionally apiculate at one end, 43.5-74 × 26.1-38.8 µm. Chemistry: TLC 3 unidentified compounds (brown-purple or greyish).
N: Volcanic Plateau southwards. S: Throughout. On bark and twigs of species of Nothofagus especially N. menziesii and N. solandri var. cliffortioides, in moderate shade or in full sun in canopy branches.
Australasian
Zahlbruckner ( loc. cit.: 337) gives a smaller spore size in his protologue, but examination of typical material did not confirm his dimensions (18-29 × 6-12 µm). P. nothofagi is closely related to P. truncata chemically and morphologically and is distinguished only by the larger spores.
