Flora of New Zealand Series

Holotype: New Zealand. Marlborough, Chetwode Is, Nukuwaitata I., 40º54's, 174º04'E, on bark, iii.1984, B.W. Hawyard s.n. – AK 206954.

Description : Thallus off-white, thin, somewhat cracked, surface smooth and somewhat shining, without isidia or soredia. Apothecia verruciform, very flattened-hemispherical, concolorous with thallus, scattered, 0.8–1.2 mm diam.; ostioles conspicuous, black, 0.2–0.3 mm diam., 1 per verruca. Ascospores 8 per ascus, uniseriate, ellipsoidal, smooth, 30–37 × 18–20 μm.

Chemistry : K−, C−, KC−, Pd−; containing 4,5-dichlorolichexanthone.

S: Marlborough (Chetwode Is). On bark. Known only from the type collection.

Endemic

Illustration : Archer & Elix (1994a: 205, fig. 4).

Pertusaria parvula is characterised by: the corticolous habit; verruciform apothecia; small ascospores; and the presence of 4,5-dichlorolichexanthone. It is superficially similar to both P. albissima and P. melaleucoides but is distinguished by the number and size of the ascospores and presence of 4,5-dichlorolichexanthone.