[GS] Pileus 7-9 mm. diam., grey, hemispherical with a shallow umbilicus and a down-rolled margin, subfibrillose, satiny; flesh very thin, fragile. Gills adnate to sinuate, pale grey with white margins, deep, moderately distant, long and short intercalated. Stipe 2-3 cm. x 1-2.5 mm., very pale fawn, smooth, silky; flesh solid, white, fragile. Spores subglobose, 4-5-7um diam., moderately thick-walled, outer layer hyaline inner layer strongly amyloid, contents or inner wall somewhat granular, apiculus prominent (Fig. 2/37, p. 37). Hymenophoral trama weakly pseudo-amyloid. Cheilocystidia thin-walled, 20-25 x 5-10um, more or less inflated. Cuticle of closely woven hyphae with thin-walled swollen dermatocystidia, 40-50 X 10-15um,, with grey contents. HABITAT : on fallen log in Nothofagus forest, Butterfly, Wellington, 8.4.1961, G. M. Taylor (type). [EH] Spores oval to almost round, hyaline, amyloid, smooth, 5-6.5 x 4-5.5 um (2-spored: 5.5-6 x 7um). Cheilocystidia present but not distinct. Caulocystidia club-shaped or somewhat irregular, thinwalled, distinctly coloured by a brown, plasmatic pigment. Cuticle of repent, cylindrical hyphae forming a cutis, with scattered clubshaped or fusoid, suberect dermatocystidia filled with a brown coloured cell sap, with clamp connections. [JAC] Singer considered this to be a young form of Hydropus dusenii. Cap with hydropoid vesciles with brown plasmatic content. Stem finely pruinose at apex with caulocystidia, like Egon's drawing of cap surface. There are spores of the type seen by Stevenson. In fact there seems to be 1-2-3-4 spored basidia with amyloid spores of a large range of shapes and sizes but all clearly associated with this Hydropus. The cheilocystidia are not as clear as Egon's drawing. Clitocybula/Hydropus seems a reasonable placement but no decision until generic boundaries are more clearly deliniated. There appear to be a number of similar greyish brown Gerronema/Hydropus/Clitocybula species in NZ and the species boundaries remain unclear.

[Notes from Kew Type specimen, PRJ 2010] Kew images.

Pileus 7-9 mm diam, grey, hemispherical with a shallow umbilicus and a down-rolled margin, subfibrillose, satiny; flesh very thin, fragile. Gill adnate to sinuate, pale grey with white margins, deep, moderately distant long and short intercalated. Stipe 2-3 cm x 1-2.5 mm, very pale fawn smooth, silky; flesh solid, white, fragile. Spores subglobose 4.5-7 µm diam. moderately thick-walled, outer layer hyaline inner layer strongly amyloid contents or inner wall somewhat granular, apiculus prominent (Fig. 2/37 p. 37). Hymenophoral trama weakly pseudo-amyloid. Cheilocystidia thin-walled 20-25 x 5-10 µm, more or less inflated. Cuticle of closely woven hyphae with thin-walled swollen dermatocystidia, 40-50 x 10-15 µm, with grey contents.

On fallen log in Nothofagus forest, Butterfly, Wellington, 8.4.1961 G. M. Taylor (type).

Pileus 7-9 mm diam, griseus, hemisphaericus, cum umbilico levi et margine deorsum revoluto, subfibrillosus, nitenti-sericeus; caro tenuissima, fragilis. Lamellae adnatae usque sinuatae, pallide griseae, marginibus albis altae, modice distantes, longiores cum brevioribus intercalatae. Stipes 2-3 cm x 1-2.5 mm, perpallide hinnuleus, laevis, sericeus; caro solida alba, fragilis. Sporae subglobosae, 4.5-7 µm diam., parietibus modice crassis strato exteriore hyalino interiore valde amyloideo, materie inclusa vel pariete interiore subgranulari, apiculo prominente. Trama hymenophoralis leviter pseudo-amyloidea. Cheilocystidia 20-25 x 5-10 µm, parietibus tenuibus velut cellulae vesiculosae. Cuticula ex hyphis dense intertextis sisteus, dermatocystidiis tumidis cum parietibus tenuibus 40-50 x 10-15 µm, materie inclusa grisea.

Typus: G. M. Taylor 78.