AUSTRALIA. Victoria, Eildon-Jamieson road, Big River bridge, hypogeal in mixed eucalyptus forest, 13 Sept. 1973, K. & G. Beaten 21; Rubicon, Royston road, hypogeal in wet eucalyptus forest, 16 May 1974, K. & G. Beaton, Apollo Bay, Maits Rest, in wet eucalyptus forest, 19 July 1982, K. & G. Beaton 41; Eildon-Bonnie Doon road, hypogeal in dry, mixed eucalyptus forest, 16 Aug. 1982, A. C. Beauglehole, K. & G. Beaton-, Portland, Lower Gleneig Nat. Park, River road, hypogeal under Melaleuca leucodendron L., 16 Sept. 1982, H. & C. Campbell & Y. Compton, Cathedral Range, Cathedral Park, Blackwood Flat, hypogeal under Eucalyptus radiata Sieber, 10 May 1983, K. & G. Beaton. TASMANIA. Rodway 117 (type of H. albellus, K). SCOTLAND. Glasgow, Botanic Garden, Oct. 1830, Hooker fit. (lectotype of H. albus, K).

asterocarp 0.5-2 cm diam., subglobose to pyriform, basally attached. Peridium thin, dingy white to pallid yellowish brown, glabrous, at times cracking, floccose and partially detersile. Gleba pale brown to ferruginous, loculate, of irregular, empty or partially filled chambers, very variable in size, without radial arrangement. Tramal plates up to 175 µm thick, white, with a narrow hymenophoral trama and very broad subhymenial layers; clamp-connexions present on all hyphae. Sterile base minute or none.
Spores 14-17(-19.5) x 7.5-11.5(16 ± 1 x 10 ± 0.5) µm (excl. myxosp.), Q = 1.6; limoniform, deep golden brown to fuscous brown, with a thickened wall bearing a coarsely rugulose exosporial ornamentation, overlain by a loose membranous, hyaline myxosporium. Basidia 28-33 x 9-11 µm, clavate, bearing two short sterigmata, and forming a regular palisadic hymenium. Hymenophoral trama regular, hyaline, of inflated, thin-walled hyphae, 3-18 µm diam. Subhymenial layer very well developed, 20-30 µm wide, pseudoparenchymatous. Peridiopellis an agglutinated, stratified epithelium, of hyaline, thin-walled elements, 26-40 x 13-30 µm, globose to pyriform.

Berkeley (1836: 229) gave the name 'Rhizopogon albus Bull.' to material collected by J. D. Hooker in the Botanic Garden, Glasgow, and this material was sent to Klotzsch. Klotzsch (1839) matched this to material gathered in the botanic garden at Grunewald, near Berlin, and redescribed it as Hymenangium albus Klotzsch, type species of the genus Hymenangium Klotzsch. The Glasgow specimens, labelled 'Hymenangium album' by Klotzsch are now located in the Kew Herbarium, whilst the Grunewald material is lost. Dodge & Zeller (1934: 641) recorded collections from many north temperate localities, in both Europe and North America, but commented that it was usually collected in pots of cultivated plants in greenhouses, often associated with eucalyptus, and Hawker (1954: 535) did not regard this species as indigenous in Western Europe. Cribb (1956: 126) confirmed the occurrence of H. albus in Australia, after matching Queensland collections to the Glasgow material. It is likely that Cribb accepted a broad species concept for she commented on the exceptional variability of the spore form, and her illustrations would suggest that some of the collections included H. zeylanicus and H. nanus in addition to H. albus. Examination of. H. albellus, based on gasterocarps gathered in Tasmania by Rodway, confirms this to be a later synonym of H. albus.
The mucronate spores and epithelial peridiopellis indicate a close affinity with H. zeylanicus, differing in the shorter and less fusoid spore-form. This is the most common and plentiful species of Hymenogaster in Victoria State.