Menegazzia lucens P.James & D.J.Galloway
* Account prepared by P.W. James (BM).
Holotype: New Zealand. Canterbury, Governor's Bush, Mt Cook National Park. On peeling bark of Nothofagus menziesii, c. 800 m. H.D. Wilson 1970, 12 March, 1971. CHR 260683!
Thallus closely attached, forming regular or irregular, complete or partial rosettes, or encircling twigs or small branches, to 10 cm diam., sometimes coalescing to form more extensive colonies. Lobes numerous, ± radiating towards outer edges, uniform, (1.5-)2-3(-3.5) mm wide, remaining distinct to centre, or ± obliterated by imbricate laterals, frequently branched, terminal lobes ± palmate, contiguous throughout entire length, often imbricate, becoming ± compressed and convolute-distorted centrally, margins sinuous-contorted, entire or occasionally notched, short, digitate laterals often present, not, or sparingly blackened, apices concolorous or ± suffused pale brown, hollow, lower side of internal cavity pale at tips, black centrally. Upper surface convex, uniformly pale grey, faintly white-maculate or emaculate, ± rugoseuneven or notably crumpled, shining, without isidia or soredia. Perforations frequent, median on main lobes, also on short laterals, small, 0.2-1.0(-1.5) mm diam., ± elevated, becoming low-conical or truncate, sometimes with a distinct margin, rounded at first, becoming ellipsoid. Apothecia frequent, scattered or crowded, adnate, rarely turbinate, to 4(-4.5) mm diam., margins thin at first, smooth, entire, becoming irregularly lacerate-crenulate, ± elevated, disc concave to plane, pale brown, rarely dark brown, epruinose. Epithecium pale brown to brown, transparent in section, densely inspersed with numerous, minute, pale brown granules extending into upper part of hymenium. Hymenium 100-130 µm tall. Asci 90 × 40 µm, 2-spored. Ascospores shortly ellipsoid, 44-48(-57) × 25-31(-35) µm, wall (2-)3-3.5 µm thick. Chemistry: Two chemodemes present in N.Z. populations. i: alectoronic acid and UV- unidentified compounds. ii: alectoronic and r-collatollic acids and UV- unidentified compounds (different from i), atranorin; medulla K-, C-, KC+ pink, Pd-, UV+ vivid ice-blue (alectoronic acid).
N: Wellington (Whakapapa, Mt Ruapehu, York Bay). S: Nelson to Fiordland, inland and east of or close to the Main Divide from lat. 42°S, Banks Peninsula and coastal Otago and Southland. A: On bark of trees and shrubs at forest margins or in grassland, s.l. to 1000 m.
Endemic
M. lucens is distinguished by its 2-spored asci, the granular epithecium, the often distinctly wrinkled-crumpled upper surface and the UV+ vivid ice-blue medulla (alectoronic acid). It is possible that the circumscription above may represent two separate species since the west coast populations (South I.) are chemodeme i and have predominantly digitate-adventitious lobules arising from the main lobes. M. ultralucens is the sorediate counterpart of chemodeme ii.
