Menegazzia nothofagi (Zahlbr.) P.James & D.J.Galloway
* Account prepared by P.W. James (BM).
Holotype: New Zealand. Wellington, Raetihi, c. 600 m on Nothofagus menziesii, J.E. Attwood A34, W!
Thallus rosette-forming at first, becoming irregular and forming extensive, ragged-edged patches, individual thalli seldom exceeding 5 cm diam., corticolous, rarely saxicolous or terricolous. Lobes very numerous, small, delicate and fragile, 0.5-0.8 mm wide and to 5 mm long but usually much shorter, irregularly branched, sometimes subpalmate towards perimeter, mostly closely contiguous throughout entire length, often imbricate centrally and there sometimes ± ascending, margins sinuous, entire or notched, hollow, lower side of internal cavity blackened, apices ± elevated, ± pale brown or red-brown. Upper surface concave or plane, shining, pale green-grey or fresh lettuce-green, in exposed situations becoming suffused-brownish, margins not, or only sparingly, blackened, with a faint, white, irregular, incomplete reticulum of maculae (×10 lens) best seen at apices and margins. Perforations numerous, median on main lobes, depressed, oval or rounded, gaping, with an inrolled edge (pertransita -type), 0.2-0.5 mm diam. Soredia arising from upper surface and margins of perforations, derived from erosion of isidia-like vesicles. Vesicles at first simple, or several closely contiguous, hollow, nodular, proliferating to form verruciform clusters which eventually cover older parts of thallus, often apically abraded. Apothecia not seen. Chemistry: Stictic, constictic, norstictic (tr.) and menegazziaic acids and atranorin (±); medulla K+ yellow → orange, C-, KC+ orange, Pd+ orange.
N: North Auckland (Kawerua) to Wellington. S: Nelson (St Arnaud Ra.) to Southland (Waihopai Scenic Reserve, Invercargill), both east and west of the Main Divide from lowland-coastal forest to subalpine vegetation at tree-line. St: Mainly on bark of forest trees, rarely on rocks in dry, open Leptospermum scrub or among mosses on rocks or on the ground.
Australasian
M. nothofagi is a small, narrow-lobed, rather ragged-looking species, with plane to convex lobes, usually green and suffused brownish at apices, which also have a white maculate reticulum. Soredia arise from the bursting of coarse isidia-like vesicles which may be so numerous as to obscure central parts. In some specimens soredia are not well developed, but the ruptured vesicles are characteristic. The species is closely related to M. eperforata, however this latter species is devoid of any laminal perforations and has true isidia.
