Flora of New Zealand Series

Holotype: New Zealand. Nelson, Mt Arthur, track to hut, 41º12's, 172º44'E, 1080 m, on bark of fallen Nothofagus menziesii, 14.ix.1995, W.M. Malcolm 2562 – CHR 507218. Isotypes – CANB, NSW.

Description : Thallus off-white to pale-grey, thin, cracked or effuse, surface smooth and dull, without isidia or soredia. Apothecia verruciform, strongly flattened-hemispherical, scarcely rising above thallus surface, scattered, conspicuous, grey-black to greenish, 1–2 mm diam.; ostioles inconspicuous, black, 0.05–0.1 mm diam., 1–2 per verruca. Ascospores 8 per ascus, ellipsoidal, smooth, uniseriate, (50–)60–65(–75) × 25–30 μm.

Chemistry : TLC−, all reactions negative.

S: Nelson (Mt Arthur, Murchison, Matakitaki west bank road), Canterbury (N of Cass). On bark of Nothofagus menziesii and N. solandri var. cliffortioides, in montane beech forest. Probably more widely distributed than records presently show.

Endemic

Illustration : Archer & Malcolm (1997: 486, fig. 1).

Pertusaria spilota is characterised by: the corticolous habit; the scattered, inconspicuous, markedly flattened verrucae; the 8-spored asci; and the absence of secondary chemistry. It is distinct from P. albissima Müll.Arg., which also has 8-spored asci and no chemistry, but numerous, conspicuous verrucae (Archer & Elix 1994a).