Flora of New Zealand Series

Thallus crustose, smooth, verrucose, cracked or wrinkled, whitish, cream, greyish-white to olive greenish-grey, corticolous or saxicolous, rarely terricolous. Photobiont green, Protococcus. Apothecia lecanorine, sessile or subpedicellate or ± immersed, 1-7 mm diam., thalline exciple prominent, concolorous with thallus, disc concave to convex, matt or pruinose, smooth or wrinkled or corrugate-cracked. Hymenium tall. Paraphyses branched, net-like. Asci clavate, I+ blue, with corona and amyloid tholus, 2-8-spored. Ascospores colourless, unicellular, large, usually longer than 30 µm, ellipsoid, thick walled.

Ochrolechia is a widespread, cosmopolitan genus of c. 40 described species included in the family Pertusariaceae. Species occur on bark and rock and rarely on soil, and are characterised by the ± white, spreading, encrusting thallus and the prominent lecanorine fruits containing large, thick-walled spores. Taxonomic accounts of Verseghy [ Beih. Nova Hedwigia: 1-146 (1962)] and Howard [ Bryologist 73: 93-130 (1970)] contain useful information but a satisfactory monograph is still needed. Antarctic species are discussed by Lindsay [ Bull. Br. Antarct. Surv. 26: 77-83 (1971)]. The genus in New Zealand is much in need of collection and study; four species are recorded here.