Menegazzia aeneofusca (Müll.Arg.) R.Sant.
* Account prepared by P.W. James (BM).
Parmelia aeneofusca Müll. Arg., Flora 66: 77 (1883).
Thallus ± orbicular, in closely-attached often regular rosettes, or spreading, to 8 cm diam., saxicolous. Lobes rather short, to 1.5(-2.0) mm wide, irregularly dichotomously branched, not extended at apices, ± strongly contiguous at margins, ± congested-imbricate centrally, outer lobes smooth, glossy, centrally wrinkled-scrobiculate or corrugate, matt, margins rounded or shallowly incised, olive-green or brown or blackened, sometimes pale green-grey centrally, apices chestnut-brown, glossy, often grey-white-maculate, internal cavity black. Perforations rather large, infrequent, to 1 mm long, ± oval, in median line of lobes, plane with surface of lobes. Lower surface black, shining, glabrous, markedly scrobiculate, brownish at margins, eperforate. Apothecia often frequent, central, 0.5-2.5 mm diam., sessile, rounded, disc concave to ± plane, red-brown to dark brown, shining, epruinose, exciple smooth, shining, ± ridged, margins thick, entire, shining, concolorous with thallus. Epithecium granular, pigmented. Ascospores 2 per ascus, smooth, oval 44-52 × 17-20 µm, wall 3 µm thick. Chemistry: Stictic, constictic, norstictic and menegazziaic acids and accessory substances, medulla K+ yellow → orange, C-, KC+ orange, Pd+ orange.
S: Nelson (St Arnaud Ra.) east of Main Divide to Otago (Dart River) and eastern foothill ranges at Dansey Pass. St: (Mt Anglem, Glory Cove). Alpine-subalpine on rocks or amongst mats of Andreaea, 700-2000 m (s.l. in St: - Glory Cove).
Australasian
M. aeneofusca and its sorediate counterpart M. castanea are the only exclusively saxicolous species of the genus. Both occur on alpine and subalpine rocks. M. aeneofusca is distinguished by its often ± regular rosettes, the dark colour and the 2-spored asci.
