Lecidea demersa Kremp.
L. melastroma Nyl., Lich. N.Z.: 107 (1888).
Holotype: New Zealand. Sine loco (prob. Wellington). Charles Knight, M 123-80/6!
L. melastroma. Holotype: Nova Zelandia. Westland, Greymouth, Richard Helms, 241, 1887, H-NYL 16081!
Thallus in orbicular to spreading patches, 2-10(-20) cm diam., whitish or grey-white, areolate, areolae minute, irregular, thick black prothallus visible between areolae giving a marbled appearance to thallus, surface smooth, matt, Apothecia orbicular, innate, disc flush with thallus surface, 0.5-1.2 mm diam., solitary or 2-4-confluent, round to irregular, disc black, matt, epruinose, smooth to ± gyrose-uneven, plane to subconvex, margins very thin, black, slightly raised. Epithecium granular, brown-black or greenish-black, 8.5 µm thick. Hymenium pale yellowish, 30 µm tall. Paraphyses dense, apically capitate, to 5 µm thick. Hypothecium pale brown or yellow-brown, to 40 µm thick. Asci clavate, 46 × 17 µm, close to surface of disc. Ascospores ellipsoid, 7-10 × 5.1-6 µm.
N: S: (Westland, Nelson). A subalpine species, spectacularly developed on the sandstone pavements of the Denniston Plateau, north of Westport.
Endemic
