Flora of New Zealand Series

≡Dimerella lutescens Vězda & Malcolm, Australas. Lichenol. 41: 35 (1997).

Holotype: New Zealand. South Island. Nelson, Hackett River, north side, 41º24.0's, 173º13.5'E, 160 m, on bark of mature Podocarpus totara in mixed beech-podocarp lowland forest, 25.ii.1996, W. Malcolm 2710 – CHR 489337. Isotypes – Herb. W. Malcolm; Herb. A. Vězda.

Description : Thallus crustose, thin, epiphloeodal, ash-green, shining in parts, without a marginal prothallus. Apothecia frequent, rounded, strongly constricted at base, 0.2–0.25 mm diam., disc yellowish or almost white, plane; margins entire, concolorous with disc. Exciple hyaline, plectenchymatous, of spherical cells. Hymenium hyaline, 40–45 μm tall. Paraphyses 1 μm diam., apices swollen to 4 μm diam. Asci clavate. Ascospores biseriate, fusiform-ellipsoidal, 7–9 × 2–2.2 μm. Pycnidia not seen.

S: Nelson. Known only from the type locality.

Endemic

Illustrations : Vězda & Malcolm (1997: 37, figs 2–3 – as Dimerella lutescens); Malcolm & Malcolm (2001: 36 – as Dimerella lutescens).

Coenogonium lutescens is characterised by: the corticolous habit; microcarpic apothecia constricted at base (0.2–0.25 mm diam.), disc white or yellowish, plane, margins flat, concolorous with disc; a low hymenium, 40–45 μm tall; and biseriate ascospores, 7–9 × 2–2.2 μm.