ARALIACEAE. Pseudopanax crassifolium: Auckland, Mt. Te Aroha, 500 m. COMPOSITAE. Olearia colensoi: Westland, Alecs Knob, 1,500 m. CONIFERAE. Dacrydium cupressinum: Wellington, Pohangina Valley, 250 m. CORIARIACEAE. Coriaria arborea: Auckland, Waitetoki, Lake Taupo, 450 m. CORNACEAE. Griselinia littoralis: Wellington, Whakapapa, Mt. Ruapehu, 1,000 m, type collection, P.D.D. herbarium, No. 11216. CUNONIACEAE. Weinmannia racemosa: Otago, Alton Valley, Tuatapere, 150 m. EPACRIDACEAE. Cyathodes fasciculata: Auckland, Mt. Te Aroha, 400 m. MYRTACEAE. Leptospermum ericoides: Auckland, Little Barrier Island. RUBIACEAE. Coprosma robusta: Nelson, Staircase Creek, Reefton, 700 m.

Hymenophore annual, membranous, closely adherent, effused forming linear areas to 12 x 5 cm; hymenial surface cream, later pallid buff, even, not creviced; margin thinning out, white, fibrillose, adherent. Context white, 30-120 µ thick, basal layer narrow, of parallel hyphae, intermediate layer of erect compact hyphae; generative hyphae 3-4 µ diameter, walls 0.5 µ thick, naked, with clamp connections. Gloeocystidia crowded in context and hymenium, forming a dense palisade, arising from the base, flexuous-cylindrical, submoniliform, or subclavate, scarcely or not projecting, 45-110 x 10-12 µ, walls 1 µ thick. Hymenial layer to 80 µ deep, a dense palisade of basidia, paraphyses, and gloeocystidia. Basidia clavate, 45-65 x 11-14 µ, bearing 2-4 spores; sterigmata stout, 8-10 µ long. Paraphyses subclavate, 30-50 x 7-10 µ. Spores oval, a few subglobose, apiculate, 8-11 x 7-8 µ, walls smooth, hyaline, 0.5 µ thick.

TYPE LOCALITY: Mt. Ruapehu, Wellington, New Zealand.
DISTRIBUTION: New Zealand.

HABITAT: Effused on decorticated dead wood.

Hymenophorum membranaceum, adherens, effusum; superficie cremea deinde pallide bubalina, non rimosa. Hyphae generatoriae fibulatae, 3-4 µ diam. Gloeocystidia flexuoso-cylindricalia vel subclavata, 45-110 x 10-12 µ. Basidia clavata, 45-64 x 11-14 µ. Sporae ovales vel aliquot subglobosae, 8-11 x 7-9 µ, parietibus levibus, hyalinis. On dead decorticated wood of Griselinia littoralis, Mt. Ruapehu, Wellington, N.Z.

Basidia are abundant and project slightly when fertile, whereas paraphyses are scanty, slender, and seldom more than half their length. Gloeocystidia are irregular both in shape and size. Many of small size are crowded near the base; others pass from the base into the hymenium, but few project. Most are submoniliform, some cylindrical and sometimes strangulated near apices. Superficially plants resemble some collections of C. patricium.
In an earlier paper (1954, p. 290) I referred the species to C. radiosum Fr. As J. Boidin has pointed out it differs from this species in the larger nonamyloid spores and presence of clamp connections.

The species is Aleurodiscus amylaceus (Bourd. & Galz.) D. P. Rogers & H. S. Jacks. Cunningham also compared it with this species (as Corticium radiosum Fr.), but rejected the synonymy, because C. vallum had clamps and inamyloid spores. The species causes a white rot.