Flora of New Zealand Series

≡Lichen membranaceus Dicks., Fasc. pl. crypt. brit. 2: 21, tab. VI, fig. 1 (1790).

≡Leproloma membranaceum (Dicks.) Vain., Természetr. Füz. 22: 293 (1899).

Description : Thallus of powdery lobes, forming irregular rosettes, yellowish white. Lobes broadening towards the tips, the thallus being poorly incised and the axils undeveloped; margins rounded, ±flat, the surface corticate of numerous powdery convex granules, the margin either flat or raised, 1–17 mm wide, older lobes often disintegrating to powdery convex granules to 0.5 mm diam., especially at centre of thallus, or becoming eroded to leave a leprose membrane. Lobes and granules covered with loosely entangled hyphae, often projecting outwards (×25 lens). Medulla whitish. Lower surface composed of a continuous, well-developed weft of branched hyphae forming a whitish grey to brownish prothallus. Apothecia not seen.

Chemistry : Thallus K− to + yellow, C−, Pd+ reddish orange; containing pannaric acid, roccellic acid, with atranorin (±) and zeorin (±) as accessories.

S: Otago (Fairfax Spur Dunstan Mts). In high-alpine fellfield. Still very poorly understood and collected in New Zealand, but probably more widespread in high-alpine habitats E of the Main Divide. The lichen is acidophilous, photophobous and nitrophobous, growing on shaded, vertical rocks, both directly on the rock surface and over mosses. Known also from Great Britain, Europe, Cape Verde Is, Scandinavia, Russia, Morocco, East Africa, Zimbabwe, Brazil, Chile and Australia (Laundon 1989: 12; Leuckert & Kümmerling 1991: 25–27; Lohtander 1995: 51; Aptroot 2002e; Becker 2002; Kukwa 2002a; McCarthy 2003c, 2006; Nimis & Martellos 2003; Santesson et al. 2004).

Bipolar

Illustrations : Dobson (1979: 139 ; 1992: 188; 2000: 214; 2005: 244); Moberg & Homåsen (1982: 221); Wirth (1987: 263; 1995b: 545); Laundon (1989: 2, fig. 1; 6, figs 4, 5); Tønsberg & Jørgensen (1997: 598. fig. 1A, B); Brodo et al. (2001: 399, pl. 448); Sérusiaux et al. (2004: 93).

Lepraria membranacea is characterised by: terricolous/saxicolous habit; the rounded, powdery sqamules with a rolled ridge at the margins, reminiscent of Normandina pulchella; the yellowish white colour; and the presence of pannaric and roccellic acids.