New Zealand: South Island, Nelson, N of Pakawau. 15.V. 1968, leg. Horak (PDD 27142, holotype; ZT 68/451, isotype).

Pileus up to 20 mm diam., plane with strongly inrolled margin, soon depressed or umbilicate; fuscous to black-brown, often with distinct silvery shine, not hygrophanous, estriate; minutely velutinous or tomentose, dry, veil remnants absent. Lamellae decurrent to arcuate, densely crowded; grey-brown young, later becoming darker with porphyry tint; edge concolorous, even. Stipe 15-20 X 1-2 mm, cylindric, central but rarely also eccentric or lateral; concolorous with pileus, base with whitish mycelium; fibrillose, dry, solid, single in groups. Odour and taste slightly farinaceous. Chemical reactions unknown. Spore print pink. Spores 6-7.5 x 4.5-6 µm, ovoid, distinctly rugulose to subangular, pale pink in KOH, membrane thin-walled. Basidia 30-35 X 6-7 µm, 4-spored. Pseudocystidia 40-50 X 5-7 µm, scattered on lamellar edges and faces, lanceolate-fusoid, hyaline, membrane thin-walled, with brownish (KOH), granular inclusion. Cuticle a cutis of irregularly interwoven, cylindric hyphae (4 - 6 µm diam.), encrusted with brown pigment, membranes not gelatinised. Clamp connections absent.

On rotten trunk of Cyathea medullaris (Forst. f.) Swartz (tree fern). New Zealand.

Pileo -20 mm. umbilicato-depresso, fuligineo, minute velutino. Lamellis adnato-decurrentibus, griseo-brunneis vel porphyreis. Stipite -20 X -2 mm, cylindrico. pileo concolori, glabro, centrico vel sublaterali. Odore sub-farinaceo. Sporis 6-7.5 x 4.5-6 µm, ovatis, rugulosis vel subangulatis. Pseudocystidiis -50 x -7 µm. Acuto-fusoideis. Hyphis defibulatis. Ad truncum putridum Cyatheae medullaris. Novazelandia.

Macroscopically R. fuliginea can be mistaken for R. dingleyi since both taxa are similar in size and colour of the carpophores. However, in microscopic detail there can be no doubt about their taxonomic separation: the size of the spores and the shape of the conspicuous pseudocystidia in the two species differ greatly.

Typus PDD 27142.