Menegazzia subpertusa P.James & D.J.Galloway
* Account prepared by P.W. James (BM).
Holotype: New Zealand. Wellington, Rangitikei Gorge. On Leptospermum, 17 June 1980, J.K. Bartlett, BM!
Thallus ± closely attached, forming regular or irregular rosettes which may coalesce to form extensive patches, or surrounding small twigs and then irregular or fragmentary, to 10 cm diam., often much less, corticolous, lignicolous or saxicolous. Lobes numerous, often noticeably radiating and contiguous at margins, ± irregular towards centre and there often imbricate, 1-2.5 mm wide, margins sinuous-contorted, sometimes notched, not, or sparingly blackened at apices, apices not suffused-brownish, blunt, hollow, lower side of internal cavity brownish-black. Perforations numerous to somewhat sparse, plane or slightly elevated, 0.5-0.8 mm diam. Upper surface pale grey or greyish-white, dull, matt, often minutely pruinose in parts, occasionally shining in parts, smooth or frequently ± corrugate-ridged (×10 lens), sorediate. Soredia numerous, laminal, not associated with perforations, often in groups or widely dispersed on the lobes, sometimes confluent, convex from the first, sometimes eventually globose, coarsely granular, white, soralia < 2 mm diam. Apothecia occasional to rare, discrete or sometimes clustered, sessile to subpedicellate, 2-4(-6) mm diam., disc concave at first, becoming plane, red-brown, epruinose, margins thin, becoming sorediate. Epithecium red-brown, 35-50 µm tall, not granular. Asci 2-spored, 90-100 × 35 µm. Ascospores 48-60 × 25-30 µm. Chemistry: Stictic, norstictic (tr.) and menegazziaic acids and accessory substances; medulla K+ yellow → orange, C-, KC+ orange, Pd+ orange.
N: Taupo to Wellington. S: Nelson to Southland, mainly east of the Main Divide in drier, lowland and coastal habitats, occasionally inland, on both introduced and native vegetation, fenceposts and gates, rocks. St: (Port Pegasus). A: C: M: Widely distributed and probably the most commonly collected sorediate species of the genus in New Zealand.
Australasian
M. subpertusa is a widespread species especially in drier areas away from the main mountain ranges. It is rather variable in morphology but the combination of 2-spored asci, stictic acid in the medulla, roughened, wrinkled surface of the lobes and soredia not associated with perforations, distinguishes it from other sorediate species in the genus. It resembles the predominantly Northern Hemisphere species M. terebrata, but the latter has a smoother thallus surface and the morphology of the soralia is different.
