Flora of New Zealand Series

Holotype: New Zealand. North Auckland, Orewa, on Pseudopanax crassifolius. J.K. Bartlett 16638a, 16 July, 1981. U.

Thallus yellowish, rather thick (60-115 µm), with scattered to crowded verrucae, 0.2-0.5 mm diam., which can become papillate and to 0.5 mm tall, sorediate. Soralia small, 0.2-1.0 mm wide, at apices of verrucae, soredia 15-35 µm diam. Apothecia scattered, 0.8-3.6 mm diam., disc plane to convex, brown, dull, sometimes slightly pruinose, margins prominent, thick, pale brown to yellowish, sometimes black, dull. Epithecium orange-to chestnut-brown to 25 µm thick. Hymenium 180-250 µm tall, I+ blue. Ascospores 2-6 per ascus, 1-septate, slightly curved, 42-60 × 25-37 µm. Chemistry: KC+ yellow, Pd-. Usnic acid and zeorin.

N: North Auckland (Herekino) to Wellington. Mainly lowland and coastal in forest remnants. On Agathis australis, Cordyline australis, Myrsine australis, Phyllocladus trichomanoides, Podocarpus ferrugineus and Pseudopanax crassifolius, 100-500 m.

Endemic

M. knightii differs from all other species of Megalospora with 1-septate spores, by the broad layer of coarse crystals in the epithecium reacting K+ yellow. It differs from M. subtuberculosa in the verrucose-papillate thallus.