Flora of New Zealand Series

Holotype: New Zealand. North I. Northland: Otamea County, Kaiwaka, 1975–1985. J.K. Bartlett 24219 (AK 192231).

Description : Thallus dull-fawn or pale olive-green, areolate, surface smooth or subtubercular, somewhat shiny, soredia present; without isidia. Soralia conspicuous, numerous, white, initially pustulate, composed of granular soredia, hemispherical or discoid, 0.5–2.0 mm diam. Apothecia not seen.

Chemistry : K−, KC−, C−, Pd+ intense-yellow; containing psoromic acid (major) and conpsoromic acid (minor).

N:. Northland (Great Barrier I., Rakitu I.), South Auckland (Mt Moehau, Coromandel Peninsula, Upper Kauaeranga Gorge), Wellington (Rimutaka Ra.). S: Nelson (Kaihoka), Marlborough (Mt Maud, d'Urville I.), Westland (between Greymouth and Runanga), Otago (Silver Peaks, Mt Cargill), Southland (Cascade Creek, Eglinton Valley). St: (Port Pegasus, Islet Cove). On Aristotelia serrata, Coprosma arborea, Dysoxylum spectabile, Metrosideros excelsa, Nothofagus menziesii, Olearia furfuracea, O. rani, Rhopalostylis sapida, s.l. to 700 m. Also in Papua New Guinea and Australia (Archer & Elix 1994a; Elix et al. 1997; McCarthy 2003c, 2006; Archer 2004a: 156).

Palaeotropical

Illustration : Archer & Elix (1994a: 205, fig. 5).

Pertusaria psoromica is characterised by: the corticolous habit; and the presence of numerous, conspicuous, white soralia, reacting K− and Pd+ intense-yellow (psoromic acid).