VICTORIA. Clarendon, 859, Herb. Cooke (type of Protoglossum luteum, K). Lorne, Erskine Falls car park, hypogeal at base of Eucalyptus globulus, 20 July 1982, Beaten 42. TASMANIA. Hobart, underground, Rodway 270 (type of H. viscidus, K).

Gasterocarp 0.5-3 cm diam., exceptionally 4-5 cm high, globose, broadly ellipsoid or pyriform, sometimes tapering below and elongate, with basal attachment but lacking a stipe. Peridium thick, orange to reddish golden (M.6YR/5.8/8.3) when fresh, drying chestnut brown, smooth and viscid eventually wrinkled with a silky sheen. Gleba at first white, progressively becoming dark brown, loculate, consisting of empty chambers, up to 2 mm diam., angular or elongate, radially arranged. Tramal plates up to 500 µm thick, hyaline, consisting of a broad hymenophoral trama and very strongly developed sub-hymenial layers; clamp-connexions present but small and inconspicuous. Sterile base present, small, white; columella absent.
Spores statismosporic and symmetric, 11.5-14.5 x 7.5-9(13.5 ± 0.5 x 8.5 ± 0.3) µm (inc. myxosp.), Q = 1.58; obovoid to ellipsoid, golden brown, with a thickened wall with finely verruculose exosporial ornamentation, enclosed in a hyaline, membranous myxosporium which often appears reticulately wrinkled. Basidia 30-40 x 9-10 µm, clavate, bearing either two or four, narrow, straight sterigmata. Hymenophoral trama regular, hyaline, of parallel, thin-walled, inflated hyphae, 3-13 µm diam. Subhymenial layer strongly developed, 40-55 µm thick, a strongly developed ixodermium, overlaying a differentiated hypodermium, ixodermium of erect and semi-erect, narrow, non-inflated, hyaline hyphae, 2-4 µm diam., embedded in a hyaline, gelatinous matrix. Hypodermium of inflated, thin-walled hyphae, 3-30 µm diam., with an orange membrane pigment, forming agglutinated clusters at 40-80 µm intervals.

Massee (1891:97) proposed the genus Protoglossum, with P. luteum as the type and only species, from Victoria State, for a subepigeal fungus with a tapering subterranean base and an apex emergent at soil level. Cunningham (1944: 50) examined the type collection and found it to represent the same species that Massee & Rodway had earlier described under the name Hysterangium viscidum. Hymenogaster viscidus is easily recognized by several unique structures, including the complexity of the gelatinized peridiopellis, and the wrinkled myxosporium on the spores. It was illustrated by Cooke (1892: pi. 18/134) and by Rodway (1911: pi. 3/8).