Nothofagus fusca (Hook.f.) Oerst., on bark of fallen branch.Otago. Kinloch, head of Lake Wakatipu, 1,250 feet, Jan. 1942, G.H.C., type collection

Hymenophore effused, to 8 x 3 cm., 1-2 mm. thick, fragile, dingy cream or isabelline, when dry dingy yellow; margin lifting, irregular, slightly inturned, cream, to 2 mm. wide, floccose; surface even, cracking, dissepiments not toothed. Pores not in strata, dingy cream in section, round or angular; irregular, 0.5-1 mm. deep, 250-500 µ diameter, or 2-5 to mm.; dissepiments 50-200 µ thick, equal, densely compacted, of parallel hyphae, margin slightly tapering, of parallel hyphae, with rounded ends, appearing finely velutinate. Context to 1 mm. thick, concolorous, loosely woven at the base, densely woven and forming a sclerotioid layer to 60 µ thick beneath the pores, crystals present; generative hypha 3-6 µ thick, thin-walled, septate, freely branched, clamp connections not seen, bridging hyphae numerous. Basidial type clavate, basidia clavate or cylindrical, to 12 x 4 µ, arranged in a dense palisade. Spores ovate, elliptical, or pip-shaped, 4.5-6 x 2-2.5 µ, hyaline, smooth.

New Zealand.

Hymenophorum ad 8 x 3 cm., 1-2 mm. crassum, fragile, cremeum, demum isabellinum. Pori angulati, irregulares, 0.5-1 mm. profundi, 250-500 µ diam.; dissepimenta 50-200 µ crassa. Contextus 0.5-1 mm. crassus, concolorous, sclerotioideus. Hypharum systema monomiticum. Hyphae generatoriae 3-6 µ crassae, ramificatae, septatae, haud fibulatae. Typus basidialis clavatus. Sporae ellipticae vel seminibus mali similis, 4.5-6 x 2-2.5 µ leves, hyalinae.

The irregular pores, colour of the hymenophore, sclerotioid layer of the context and delicate walls of the thick generative hyphae are the characters of the species.

Nothofagus fusca (Hook.f.) Oerst. Otago, Kinloch, 420 m., specimen typicum.

ARALIACEAE. Meryta sinclairii: Auckland, South-west King Island. CORNACEAE. Griselinia littoralis: Otago, Milford Sound, 60 m. FAGACEAE. Nothofagus fusca: Auckland, Waitetoki, Lake Taupo, 400 m. Otago, Kinloch, Lake Wakatipu, 420 m, type collection, P.D.D. Herbarium, No. 4182. PALMAE. Phoenix sp: Auckland, Mt. Albert, 100 m.

Hymenophore annual, adherent, tending to lift when dry, membranous, fragile, effused forming irregular areas 6-14 x 3-9 cm, 1-2.5 mm thick. Hymenial surface even, cream, isabelline, or alutaceous, deeply creviced when old; margin thinning out, lifting and sometimes inturned when dry, cream, to 2 mm wide, fibrillose. Pores not in strata, round or angular, irregular, 2-5 per mm, commonly 2-3 when old, 150-500 µm diameter, to 1 mm deep; dissepiments 50-200 µm thick, equal or slightly tapering, finely velutinate. Context white or cream, 0.2-1 mm thick, hyphae loosely intertwined near the base, densely so beneath pores, forming an intricate layer to 60 µm deep, embedding crystals and granules of yellow mucilage; generative hyphae 3-6 µm diameter, walls 0.25 µm thick, often inflated between septa, septate, freely branched, without clamp connections, many crystal encrusted and in the dissepiments encrusted with mucilage. Hymenial layer to 20 µm deep, a palisade of basidia and paraphyses. Basidia subclavate, or subcylindrical, 11-14 x 3.5-4 µm, bearing 4 spores; sterigmata erect, to 4 µm long. Paraphyses subclavate, 9-10 x 3-3.5 µm. Spores obovate, elliptical, or pip-shaped, some apiculate, 3.5-6 x 2-2.5 µm, walls smooth, hyaline, 0.1 µm thick.

DISTRIBUTION: New Zealand.

HABITAT: Bark or dead branches, associated with a white rot.

Separated from others of the section by the irregular, somewhat large pores, dense hyphal layer of the context (which may be wanting in some specimens), thin-walled large-diameter generative hyphae without clamp connections, and irregular obovate or pip-shaped spores. Plants are fragile and break into segments when dry. Collections vary somewhat in size of pores, shape and size of spores, presence or absence of crystals and/or mucilage granules encrusting hyphae. In the type, granules are present in masses between hyphae and encrusting many; in the other collections listed they were found to be scanty. In macrofeatures the species resembles P. ambigua Bres. It differs in the absence of encrusted metuloids.

TYPE LOCALITY: Kinloch, Otago.