Leptospermum ericoides A. Rich. Auckland: Little Huia, 200ft, February 1949, Mrs. E.E. Chamberlain; Little Barrier Island, 500ft, November, 1947, J.M. Dingley. Leptospermum scoparium Forst. Auckland: Anawhata Road, Waitakeres, 1,000ft, September, 1949, J.M. Dingley; type collection, P.D.D. herbarium, No. 7348; Mountain Road, Henderson, 800ft, September; 1950; J.M. Dingley; Waitakere Dam, 900ft, October, 1951, J.M. Dingley. Otago: Ryan's Creek, Stewart Island, February, 1954, J.M. Dingley. Melicytus ramiflorus Forst. Auckland: Atkinson Park, Waitakeres, 900ft, June 1953, J.M. Dingley. Nothofagus menziesii (Hook. f.) Oerst. Otago: Alton Valley, Tuatapere. 400ft, February, 1954, J.M. Dingley. Nothopanax arboreum (Forst. f.) Seem. Auckland: Mairoa, February, 1953, J.M. Dingley. Plagianthus betulinus A. Cunn. Wellington: Kitchener Park, Feilding, 100ft, January, 1954, G.H.C. Podocarpus totara Don. Taranaki: Mt. Egmont, 3,000ft, March, 1951, J.M. Dingley. Tetrapathaea tetranda (Banks & Sol.) Cheesem. Auckland: Karekare, July, 1954, J.M. Dingley.

Hymenophore annual, sometimes perennial, membranous, adnate, effused forming linear areas to 12 x 2 cm, with a few small outlying irregular islands; surface at first cream, drying pallid ochre, even, delicately pruinose, not creviced; margin thinning out, white or pallid cream, fibrillose, adnate. Context white, not zoned, 250-400 µ thick, basal layer narrow, of closely arranged mainly parallel hyphae, intermediate layer of loosely arranged mainly ascending hyphae becoming vertical and compacted beneath the hymenium, containing numerous vesicles and cystidia; generative hyphae to 4 µ diameter, walls 0.5 µ thick; hyaline, naked; branched, septate, with large clamp connexions. Hymenial. layer to 40 µ deep, of basidia, paraphyses, paraphysate hyphae, cystidia and rare gloeocystidia. Basidia clavate, not projecting, 30-35 x 6-7 µ, 4-spored; sterigmata slender, to 6 µ long. Paraphyses subclavate, smaller and narrower than the basidia. Paraphysate hyphae abundant, projecting, sometimes branched near apices, to 4 µ diameter. Gloeocystidia flexuous-cylindrical, projecting to 25 µ, often scanty, sometimes with apices slightly strangulated; 60-72 x 6-8 µ, walls 0.5 µ thick. Vesicles abundant in the intermediate layer and sometimes extending into the hymenial layer, pyriform, 10-14 µ diameter, walls 0.5 µ thick. Cystidia arising in the intermediate layer, some penetrating the hymenium and projecting to 30 µ, narrowly conical with long acuminate apices, 60-112 x 12-16 µ, finely crystal coated. Spores long-elliptical, some suballantoid, with rounded ends, 11-14 x 3.5-4 µ, walls hyaline, smooth, 0.2 µ thick.

DISTRIBUTION. New Zealand.

HABITAT. Effused on bark or decorticated dead wood.

Hymenophorum annuum, vel interdum perenne, membranaceum, adnatum, effusum; superficie cremea deinde pallide ochracea, aequa, non rimosa. Hyphae contextus fibulatae, 3.5-4 µ diam., nudae. Basidia clavata, 30-35 x 6-7 µ, 4 sporis. Gloeocystidia flexuoso-cylindricalia, 60-72 x 6-8 µ. Vesiculis pyriformibus, 10-14 µ diam. Cystidia anguste conica, 60-112 x 12-16 µ, crystallis tenuibus tecta. Sporae longo-ellipticae aliquot suballantoides, 11-14 x 3.5-4 µ, laeves, hyalinae.

Characterized by the large, narrowly conical, finely crystal-coated cystidia, oblong-elliptical somewhat large spores and paraphysate hyphae which may be branched at their apices. Gloeocystidia are scanty, confined to the hymenial region, and frequently strangulated near their apices. Cystidia vary appreciably in length and relative abundance; in some sections they may project, in others scarcely reach the hymenial surface. Occasional collections are stratose.
The species exhibits a general resemblance to P. mutata (Pk.) H. & L., differing in the cystidia, smaller pyriform vesicles, narrower spores and thinner hyphae.

Auckland: Anawhata Road, Waitakeres, 1,000ft, September, 1949, J.M. Dingley; type collection, P.D.D. herbarium, No. 7348

Hyphae hyaline, thin-walled, 2-4(-5) µm wide, with clamps at all septa. Vesicles abundant, 10-18 µm diam., stalked, not cyanophilous. Glococystidia not seen in the type specimen (which is in good condition), but present in some other collections (e.g., PDD 13684). Cystidia hyaline, conical, thick-walled, 60-120 x 12-17 µm, acute, but under the encrustation obtuse. Basidia urniform, 30-45 x 6-8 µm. Spores hyaline, thin-walled, smooth, cylindrical to curved or sigmoid, 9-14(-16) x 3-4.5 µm, not amyloid.

The species clearly belongs to Hyphoderma Wallr. and is close to H. puberum (Fr.) Wallr., differing in the presence of vesicles and in the shape and size of the spores. The inconstant occurrence of gloeocystidia is also known for H. puberum (Eriksson & Ryvarden 1975).

Holotype: on Leptospermum scoparium, New Zealand, Auckland, Waitakere Ranges, Anawhata Road, coll. J.M. Dingley, Sep. 1949 (PDD 7348).