Menegazzia ultralucens P.James & D.J.Galloway
* Account prepared by P.W. James (BM).
Holotype: New Zealand. Auckland Is, Rose I. Observation Point on Myrsine scrub. 8 January, 1963, P.W. James 992/2A, BM!
Thallus closely attached, forming irregular patches among other lichens or encircling twigs. Lobes numerous, ± radiating towards outer edge, medium, (1-)2-3 mm wide, remaining almost distinct to centre of thallus or ± obliterated, branched, often with numerous toe-like laterals giving a sympodial appearance, compressed between main lobes, contiguous throughout entire length, often imbricate, becoming compressed-contorted centrally, margins sinuous-contorted, sparingly blackened at margins or whole upper surface ± blackened, or with black spots or lines, apices ± suffused-brown, hollow, lower side of internal cavity black, becoming grey or whitish towards tips. Upper surface convex, uniformly pale grey, emaculate, almost smooth or ± rugose-uneven, matt or shining, sorediate. Perforations frequent, median on main lobes, also on short laterals, small, 0.1-1.0 mm diam., ± elevated, ± conical, rounded, becoming ± ellipsoid. Soralia rather sparse, arising from edges of perforations, also scattered on surface or on short lateral lobes, ± efflorescent, becoming convex, ellipsoid or globular, farinose- or small granular-sorediate, to 2 mm diam., scattered or ± coalecsing. Apothecia rare, < 4 mm diam., sessile, margins persistent, crenulate-uneven, occasionally lacerate, disc smooth, ± shining, concave, red-brown, epruinose. Epithecium red-brown, densely granular, 20-25 µm thick. Ascospores 2 per ascus, 45-53 × 28-31 µm, wall c. 2 µm thick. Chemistry: Alectoronic and (-collatollic acids (UV+ ice-blue) and unknown UV-accessory substances; medulla K-, C-, KC+ pink, Pd-.
N: Wellington (York Bay). S: Nelson (Stillwater), Canterbury (Banks Peninsula - Kaituna Valley), Otago (Upper Olivine Valley), Southland (Lake Hauroko). A: A rather rarely collected epiphyte of Dacrycarpus, Dacrydium, Myrsine and Nothofagus bark, coastal to subalpine.
Australasian
M. ultralucens is the sorediate counterpart of chemodeme ii of M. lucens. It is distinguished from other sorediate species in the genus by the UV+ ice-blue reaction of the medulla (alectoronic acid). It occurs in similar habitats to M. lucens but is much rarer.
