17. Aleurodiscus aurantius (Persoon) Schroeter, in Cohn Kryptogamen-Flora Schlesiens, 3, 429, 1888. Pl. 27, fig. 3; Text-fig. 17. Thelephora aurantia Pers. (Syn. Meth. Fung., 576, 1801) Fr., Syst. Myc., 1, 445, 1821. Corticium aurantium (Pers.) Sacc, Syll Fung, 6, 606, 1888. Hymenophore annual, resupinate, membranous-cretaceous, adnate, effused forming linear areas to 15 × 2 cm, hymenial surface white, becoming cream, at length deeply irregularly creviced; margin thinning out, white, adnate. Context white, 150–200μ deep, basal layer of compacted, parallel, partly gelatinized hyphae, intermediate layer a narrow zone of mainly upright hyphae embedding masses of coarse crystals; generative hyphae 2–4μ diameter, walls 0.2μ thick, hyaline, branched, septate, without clamp connexions. Hymenial layer to 80μ deep, a loose palisade of basidia, paraphyses, dendrophyses, paraphysate hyphae and gloeocystidia. Basidia clavate, 30–55 × 12–14μ, 4-spored; sterigmata arcuate, subulate, to 16μ long. Paraphyses oval, obovate, clavate or cylindrical, irregular in shape and size, to 30 × 14μ. Gloeocystidia arising in the subhymenium, mostly fusiform, some moniliform or cylindrical with rapitate apices, 30–50 × 6–18μ, walls to 1μ thick, apices usually bearing one or two spherical gemmae. Dendrophyses scanty, 2–3μ diameter, with apices scantily branched, naked; paraphysate hyphae simple, apices rounded. Spores oval or broadly elliptical. 14–17 × 9–12μ, not apiculate, walls densely clothed with fine aculeae, hyaline, 0.5μ thick, amyloid. Type Locality. Europe. Distribution. Europe, Great Britain, New Zealand. Habitat. Effused on dead branches and stems. Leucopogon fasciculatus (Forst. f.) A. Rich Wellington: Mt. Tongariro, 2,500ft, March, 1952, G. H. C. From other resupinate species. A. aurantius may be separated by the naked dendrophyses, presence of paraphysate hyphae, peculiar gloeocystidia and broadly elliptical or oval, densely aculeate, amyloid spores. Dendrophyses are scanty, branched only near their apices, and walls are naked and thin. Associated with them are numerous paraphysate hyphae which penetrate between the organs of the hymenial layer to form a loose palisade. Gloeocystidia are mostly fusiform and bear apically one or two spherical gemmae. Some are narrowly cylindrical and either moniliform or cylindrical with inflated apices. They have been erroneously interpreted as pseudophyses by earlier workers. Spore walls are densly clothed with fine aculeate processes which stain deeply in Melzer's reagent. The species resembles A. coronatus in macrofeatures, and both develop upon the same host species. Separation may be made by the presence of dendrophyses, gloeocystidia bearing gemmae and differently shaped, larger spores. Though agreeing in microstructure, in macrofeatures our collection differs from European specimens seen in Kew herbarium by the colour of the hymenial surface. Cream or pallid ochre in the New Zealand specimens, in European forms it may be flesh-colour, testaceous, pinkish-buff, yellow or ochraceous, features which alone are insufficient to separate the two. Literature Cited Cooke, M. C., 1875. Grevillea, 3, 137. Cunningham, G. H., 1956. Transactions of the Royal Society of New Zealand 84, 230. Donk, M. A., 1941. Bulletin of the Botanic Gardens, Buitenzorg, III, 17, 159. Ito, S., 1929. Botanical Magazine, Tokyo, 2, 464. Pilat, A., 1926. Annales Mycologici, 24, 207. Rogers, D. P. and Jackson, H. S., 1943. Farlowia, 1, 267–268. G. H. Cunningham, C. B. E., D.Sc., Ph.D., F.R.S., Plant Diseases Division, Department of Scientific and Industrial Research, Auckland, N.Z.