VICTORIA. Narbethong, Plantation road, hypogeal in roadside cutting, 3 June 1974, G. Beaten', Marysville, Acheron Way, hypogeal in wet eucalyptus forest, 18June 1976, G. Beaten', Marysville, Cumberland Res., hypogeal at base of a eucalyptus, 7 May 1982, K. & G. Beaten 12; 1-6 km NE of Mt Disappointment, hypogeal at base of Eucalyptus regnans F. Muell, 30 Aug. 1982, A. C. Beauglehole

Gasterocarp 10-15 mm diam., subglobose, pyriform or lobed, basally attached. Peridium dingy white when fresh acquiring yellowish tints on drying, smooth, dry and glabrous. Gleba greyish orange, drying light brown (M.1.5YR/4.8/5.5), loculate, with irregular, empty chambers, 1-3 per mm. Tramal plates up to 300 µm thick, consisting of a broad, hyaline, hymenophoral trama and well developed subhymenial layers; clamp-connexions present on all hyphae. Sterile base very small, white.
Spores 12.5-17.5 x 8-9.5 (15 ± 1.0 x 9 ± 0.5) µm (excl. orn.), Q = 1.67; broadly limoniform with a prominent mucronate apex, golden brown to fuscous, with a thickened wall (-1 µm) and a reticulate exosporial ornamentation (-1.5 µm high) overlaid by a loose, hyaline, disrupting myxosporium. Basidia 30-50 x 5-8 µm, elongate cylindrico-clavate, bearing mostly four, sometimes two sterigmata; also numerous short ellipsoid immature basidia present. Hymenophoral trama regular, hyaline, of parallel hyphae, 3-18 µm diam. Subhymenial layer well developed, 10-16 µm wide, pseudoparenchymatous. Peridiopellis a thin epicutis of repent, loosely woven, non-agglutinated hyphae, 2-4.5 µm diam.

Hymenogaster reticulatus was originally described from South Australia, but was also reported from Tasmania (Cunningham 1944: 53). It is closely related to H. macrosporus but is easily distinguished by the much smaller spores and the presence of tetrasporic basidia. Hymenogaster subtropicus Cribb, from Queensland, also belongs in this group with reticulately ornamented spores but has a bluish green peridium and smaller spores.
It is interesting to speculate on the possible origin of the reticulate-spored species of Hymenogaster, for such a pattern of ornamentation is not found elsewhere in the Cortinariales but is reminiscent of that found in certain species of the bolete genus Austroboletus (Corner) Wolfe, of which several species extend into Australasia.