Hymenophore annual, membranous, adnate, effused forming irregular linear areas 0.5-6 x 0.5-1.5 cm, with numerous scattered outlying islands; surface white, then pallid cream, even, not creviced; margin thinning out, white, arachnoid, adnate. Context white, 50-70 µ thick, basal layer of a few repent hyphae, intermediate layer of sparse ascending hyphae branched more freely in the subhymenium; generative hyphae 3-4 µ diameter, walls 0.25 µ thick, hyaline, naked, branched, septate, with clamp connexions. Hymenial layer to 25 µ deep, a palisade of basidia, paraphyses and gloeocystidia. Basidia subclavate, 14-18 x 4-5 µ, 4-spored; sterigmata delicate, erect, to 6 µ long. Paraphyses subclavate, similar to but shorter than the basidia. Gloeocystidia arising from the basal layer, projecting for the greater part of their length; cylindrical. 70-105 x 5-7 µ, apices rounded, walls 0.5 µ thick, collapsing. Cystidia arising from the basal layer and confined to the intermediate layer, fusiform or conical. 16-24 x 5-8 µ, coated with deciduous rod-shaped crystals imbricately arranged. Vesicles scanty, arising from the basal layer and confined to the context, occasionally appearing as paraphysate hyphae in the hymenium, 16-20 x 4 µ, capitate apices 5-6 µ across. Spores obovate, oval, broadly elliptical, a few pip-shaped, 5-6 x 3-4 µ, walls smooth, hyaline, 0.2 µ thick.

DISTRIBUTION. New Zealand.

HABITAT. Effused on decayed decorticated wood.

Hymenophorum annum, membranaceum, adnatum, effusum; superficie alba deinde cremea, aequa, non rimosa. Hyphae contextus fibulatae, 3-4 µ diam., nudae. Basidia subclavata, 14-18 x 4-5 µ, 4 sporis. Gloeocystidia cylindricalia, eminentia, 70-105 x 5-7 µ, corruentia. Vesiculis raris, capitatis, ad 6 µ diam. Cystidia fusiformia vel conica, 16-24 x 5-8 µ, crystallis linearibus deciduis tecta. Sporae obovatae, ovales vel late ellipticae, 5-6 x 3-4 µ, laeves, hyalinae.

From the two preceding species [P. vesiculosa, P. utriculosa] this delicate plant may be separated by the simple vesicles, small unusual cystidia, and thin-walled projecting gloeocystidia. Cystidia are confined to the context, fusiform or narrowly conical and coated with coarse rod-shaped deciduous crystals imbricately arranged. Gloeocystidia are cylindrical, project for more than half their length, and collapse soon after reaching maturity. Vesicles arise from the basal layer as simple hyphae with capitate apices. Similar organs are present in the hymenium, developing as capitate paraphysate hyphae. The specific name has been chosen to indicate the modest nature of the cystidia.

Dacrydium cupressinum Sol. Auckland: Hauhangaroa Range, Taupo, 2,000ft, March, 1953, J.M. Dingley; type collection, P.D.D. herbarium, No. 12513.