TASMANIA. Wellington Falls, Feb. 1902, Rodway (type HO 58255). VICTORIA. Rubicon, Royston road, partially exposed in mixed eucalyptus forest, 16 May 1982, K. & G. Beaton 17; Beech Forest, Elliot's Track, sub-hypogeal in open area, 17 July 1975, A. W. Bennett in Beaton 67.

Gasterocarp 1-2 cm diam., subglobose, with basal attachment. Peridium very thin, chrome yellow (M.4Y/7.5/10.9) when fresh, drying caramel brown, dry, pruinose, glabrescent. Gleba dull greyish brown to ferruginous, loculate, with very small, compressed, irregular chambers, 3-5 per mm, with little or no radial arrangement. Tramal plates narrow, 25-40 µm thick, hyaline, with a broad hymenophoral trama and poorly developed subhymenial layers; hyphae 3-20 µm diam., thin-walled, lacking clamp-connexions. Sterile base scarcely present.
Spores statismosporic, orthotropic, mostly symmetric but many abnormal and asymmetric, 10.5-18 x 5-9.5(15 ± 1 x 6.3 ± 0.5) µm, Q = 2-4; elongate-fusoid with a tapering apex, with a thickened, yellowish brown wall, smooth. Basidia 20-25 x 7.5-10 µm, short clavate, bearing two short, straight sterigmata. Cystidia absent, but numerous inflated, isodiametric brachycystidia present between the basidia. Hymenophoral trama regular, hyaline, of parallel, thin-walled hyphae, 3-16 µm diam. Subhymenial layer very narrow, interwoven. Peridiopellis a thin epicutis, 10-30 µm thick, of repent, interwoven, thin-walled, non-inflated hyphae, 2.5-7 µm diam., with a yellow encrusting pigment; surface hyphae often erect or semi-erect but not forming a true trichodermium.

Hymenogaster aureus was described from Tasmania, and has been subsequently recorded from Queensland by Cribb (1956: 126) but was not hitherto known from Victoria. The brightly coloured gasterocarp occurs solitary, and is usually found only partially buried in the soil. The spores appear quite smooth under the light microscope but scanning micrographs reveal a very fine rugosity. Hymenogaster fusisporus (Massee & Rodw.) G. H. Cunn., also from Tasmania, is very similar but has a dull ochre brown peridium and hyaline, larger spores.