ARAUCARIACEAE. Agathis australis: Auckland, Waipoua Kauri Forest. FAGACEAE. Nothofagus fusca: Nelson, Golden Downs, 350 m. CUPRESSACEAE. Pseudotsuga douglasii: Auckland, Mt. Eden, 120 m; Rangitoto Island; Rotorua, 450 m. South Australia, Beaumont, Adelaide. PINACEAE. Pinus radiata: Auckland, Waipu; Whangarei; Oratia. Larix europaeus: Auckland, Mt. Albert, 50 m; Rotorua, 400 m. PODOCARPACEAE. Dacrydium cupressinum: Auckland, Epsom Show Grounds pavilion.

Hymenophore annual or perennial when stratose, adherent, ceraceous, brittle, effused forming linear areas 5-12 x 3-5 cm, 1-3 mm thick. Hymenial surface even, pallid cream, or sulphur yellow, when dry creviced, sometimes nodulose; margin irregular; lighter in colour, 2 mm or less wide, adherent, thinning out, fibrillose. Pores in strata, or not, round or angular, 5-6 per mm, 120-200 µm diameter, to 1.5 mm deep in each layer, dissepiments 200-275 µm thick, even, equal. Context pallid cream, 200-350 µm thick, of intertwined hyphae embedding crystals; skeletal hyphae 3.5-4 µm diameter, walls to 1.5 µm thick, aseptate, sparsely branched; generative hyphae 1.5-2 µm diameter, walls 0.2 µm thick, branched, septate, with abundant clamp connections, frequently encrusted with mucilage granules. Hymenial layer to 25 µm deep, a dense palisade of basidia and paraphyses. Basidia subclavate or cylindrical, 10-14 x 3.5-4 µm bearing 4 spores; sterigmata erect, to 4 µm, long. Paraphyses subclavate or cylindrical, sometimes obovate, 8-12 x 3-3.5 µm. Spores allantoid, 3.5-4.5 x 1-1.5 µm, walls smooth, hyaline, 0.1 µm thick.

DISTRIBUTION: Europe, North America, Australia, New Zealand.

HABITAT: Bark or decorticated wood of standing stumps, trunks, and worked timber, associated with a brown rot.

Specific features are the sulphur colour of the fragile hymenophore, moderate size of pores, thick dissepiments, allantoid spores, and usually one layer of pores. In two collections growing vertically on stumps, pores are stratose and arranged in small knobs as if plants were pileate. This condition has been named P. xantha forma pachymeres J. Eriksson (1949, p. 22). The species causes a destructive decay of building timbers, wood used in boat construction, and the like. Lowe (1958, p. 104) listed as additional synonyms P. greschkii Bres. and P. sulphurella (Peck) Sacc.

TYPE LOCALITY: Europe.