MYRTACEAE. Metrosideros fulgens: Wellington, Upper Pohangina River, 200 m, type collection, P.D.D. herbarium, No. 17437; Ruahine Ranges, 300-400 m.

Hymenophore annual, cretaceous, adherent, brittle, arescent, forming irregular elliptical colonies 5-20 mm long, sometimes merging to form linear areas to 15 x 2 cm; hymenial surface at first dingy white or ivory, becoming straw colour or pallid isabelline, even, not creviced; margin thinning out, adherent, white, fibrillose. Context white, 60-110 µ thick, basal layer narrow, of a few repent hyphae, intermediate layer of elect crowded hyphae embedding masses of gloeocystidia and crystals; generative hyphae 2-2.5 µ diameter, walls 0.1 µ thick, naked, with clamp connections. Gloeocystidia scattered or more usually crowded in hymenium and context, clavate, oval, or subglobose, 6-12 x 6-8 µ. Hymenial layer to 30 µ deep, a close palisade of basidia, paraphyses, and gloeocystidia. Basidia subclavate, a few cucurbitiform, 12-16 x 4-5 µ, bearing 2-4 spores; sterigmata slightly arcuate, slender, to 4 µ long. Paraphyses subclavate, 10-14 x 4-5 µ. Spores elliptic-obovate, or as often pip-shaped, 5-6.5 x 3.5-4 µ, walls smooth, hyaline, 0.1 µ thick; often adhering in pairs or fours.

TYPE LOCALITY: Pohangina River, Wellington, New Zealand.
DISTRIBUTION: New Zealand.

HABITAT: Living bark of lianes.

Hymenophorum cretaceum, arescens, adnatum, effusum; superficie sordide alba, deinde straminea vel pallide isabellina, non rimosa. Hyphae generatoriae fibulatae, 2-2.5 µ diam. Gloeocystidia clavata, ovalia vel subglobosa, 6-12 x 6-8 µ. Basidia subclavata, 12-16 x 4-5 µ, 2-4 sporis. Sporae ellipticae vel obovatae, saepe attenuato-afibulatae, 5-6.5 x 3.5-4 µ, parietibus levibus, hyalinis. On bark of living Metrosideros fulgens, Pohangina River, Wellington, N.Z.

Characters of the species are the closely adherent, brittle, chalky fructifications attached to bark of living climbing stems of Metrosideros fulgens, thin context packed with crystals, small irregular gloeocystidia crowded in context and hymenial layer, and small usually pip-shaped spores often adhering in pairs or fours.

Hymenial surface even to minutely waned, pale olivaceous brown; margin white. Basal hyphae hyaline, thin-walled, 1.5-2.5 µm wide, with clamps. Vesicles broadly ellipsoid to ovoid, 10-14 X 6-8.5 µm. Basidia clavate, 12-15 X 3.5-4.5 µm. Spores hyaline, smooth, thin-walled, broadly ellipsoid to pip-shaped, 4-5 x 2-3 µm, not amyloid.

The cretaceous basidiome, the vesicles, and the small, clavate basidia make this species a typical member of the genus Parvobasidium Jülich. The type of rot is indistinct, but seems to be brown.