This species belongs in Oligoporus Bref. because of the resupinate basidiocarp, monomitic hyphal system with clamps at the septa, and the brown rot. Spores of O. manuka are cylindrical to allantoid and 6-7.5 x 2-2.5 µm, which is larger than the measurements given by Cunningham (1947, 1965) of 5-6 x 1.5-2 µm.

Holotype: PDD 4122 - New Zealand, Taupo, Mt Tongariro, Jan. 1940, G.H. Cunningham, on Leptospermum scoparium J.R. & G. Forst.

Auckland. North slope of Mt. Tongariro, 2,500 feet, Jan. 1940, G.H.C. type collection; Same locality, 2,500-4,000 feet, Jan. 1947, G. H.C.; Banks of Oturere River, east slope of Mt. Tongariro, 2,500 feet, Dec. 1946, G.H.C.; Banks of Pangarara River, east slope of Mt. Tongariro, 3,000 feet, Dec. 1946, G.H.C.; Bank of Tongariro River, Kaimanawa Range, 2,000 feet, Dec. 1946, G.H.C.

Hymenophore effused, elliptical, to 4 x 1 cm., 0.25-1 mm. thick, firm, at first chalky white and translucent, becoming dingy cream, isabelline or sometimes reddish-brown when dry, waxy; margin not lifting, sharply defined, abrupt, 0.5 mm. or less in width, white, floccose, irregular; surface even, dissepiments not toothed. Pores round or slightly angular, not in strata, white or pallid cream in section, to 1 mm. deep, 100-250 µ diameter, 2-3 or 3-4 to mm., irregular in size and shape; dissepiments to 200 µ thick, somewhat thicker in old and young specimens, equal, of woven hyphae, apex tufted with a dense mass of hyphae. Context 100-200 µ thick, woven, white or pallid cream; generative hyphae hyaline, 3.5-4 µ thick, lumen about 1 µ, branched, septate, clamp connections and bridging hyphae abundant, swollen slightly at the septa. Basidial type merulioid, basidia clavate or subclavate, to 12 x 4 µ, cemented into a dense permanent palisade. Spores allantoid, appreciably curved, 5-6 x 1.5-2 µ, hyaline, smooth.

DISTRIBUTION: New Zealand.

HABITAT: Leptospermum scoparium Forst., on bark and wood of standing fire-killed stems and branches.

Hymenophorum ad 4 x 1 cm., 0.25-1 mm. crassum, firmum, album, demum cremeum cereamque. Pori rotundati vel leviter subangulati, 0.5-1 mm. profundi, 100-250 µ diam.; dissepimenta 100-200 µ crassa. Contextus 100-200 µ crassus, albus, textilis. Hypharum systema monomiticum. Hyphae generatoriae 3.5-4 µ crassae, ramificatae, septatae, fibulatae. Typus basidialis merulioideus. Sporae allantoideae, 5-6 x 1.5-2 µ, leves, hyalinae.

Characters of the species are the firm, usually cream-coloured waxy hymenophore, moderately thick though somewhat unequal dissepiments, thick-walled glassy hyphae of the context, merulioid basidial type and allanoid [sic] spores. The specific name has been taken from the Maori name of the host, upon which the fungus is common in the National Park.

Hab.: Leptospermum scoparium Forst. Auckland, Mt. Tongariro, 820 m., specimen typicum.

MYRTACEAE. Leptospermum scoparium: Wellington, Mt. Tongariro, 850 m, type collection, P.D.D. herbarium, No. 4122; Same region, 700-1,350 m; Pangarara River, Mt. Tongariro, 1,000 m; Upper Waikato River, Kaimanawa Ranges, 600-750 m. UNKNOWN HOST. South Australia, Waterfall Gully.

Hymenophore annual, adherent, membranous-ceraceous, effused forming linear or elliptical areas 2-4 x 0.5-1 cm, 0.25-1 mm thick. Hymenial surface at first chalk white and translucent, drying dingy cream, isabelline, or sometimes reddish-brown, not creviced; margin adherent, sharply defined, 0.5 mm or less in width, white, fibrillose, irregular, adherent. Pores not in strata, round or slightly angular, 2-3 or 3-4 per mm, 100-250 µm diameter; to 1 mm deep, dissepiments 160-200 µm thick, equal, apices tufted. Context white or pallid cream, 100-200 µm thick, of closely intertwined hyphae; generative hyphae 3.5-4 µm diameter, walls 1-1.5 µm thick, branched, septate, slightly swollen at septa, with clamp connections. Hymenial layer to 25 µm deep, a dense palisade of basidia and paraphyses embedded in mucilage. Basidia subclavate, 8-12 x 3.5-4 µm, bearing 4 spores; sterigmata erect, slender, to 4 µm long. Paraphyses subclavate, 6-10 x 3-3.5 µm. Spores allantoid, 5-6 x 1.5-2 µm,walls smooth, hyaline, 0.1 µm thick.

DISTRIBUTION: Australia, New Zealand.

HABITAT: Bark and wood of standing fire-killed stems and branches, associated with a brown ring rot.

Common in the Tongariro National Park and vicinity, the fungus produces a conspicuous brown ring rot in its host. It may be identified by the monomitic hyphal system, allantoid spores, and waxy fructifications, which form narrow linear areas upon the host tissues. Although sterile, the Australian collection has been placed here as it agrees in other features. The specific name was taken from the Maori name for Leptospermum scoparium.

TYPE LOCALITY: Mt. Tongariro, Wellington.