VICTORIA. East Gippsland, N side of Mt Buck, under rain forest leaf debris, 24 May 1964, G. A. Crichton 99; Eildon, Snobs Falls, hypogeal in loose soil under dense regrowth scrub, 3 June 1974, Beaton 74.
NEW ZEALAND. Auckland, Swanson-Filter Track, April 1948, J. M. Dingley (Ex-PDD 6171).

Gasterocarp 0.5-2.5 cm diam., globose to irregularly ellipsoid, basally attached, at times laterally coalescent. Peridium pure white to pale salmon pink or ochraceous, dry, smooth, glabrous, narrowly exposing the gleba at base in old specimens. Gleba greyish orange (M.6.5YR/5.1/5.1), labyrinthoid to loculate, consisting of empty, irregular or elongated, minute chambers, 0. 5-1.5 mm diam., elongated in basal region, without any radial arrangement. Tramal plates 50-120 µm thick, not gelatinized, consisting of a broadly hymenophoral trama and extremely narrow subhymenial layers; peridial context of slightly inflated, thin-walled hyphae, 3-15 µm diam.; clamp-connexions absent. Columella absent or rudimentary, not gelatinized; sterile base generally absent, rarely present. Spores 8-12 x 6.5-10.5(10 ±0.8 x 9 ±0 5) µm, Q= 1.10; asymmetric, cuboid, with four or five angles visible in lateral view, pinkish brown, with a slightly thickened smooth wall, and containing a single, large oil guttule. Basidia 22-33 x 5-l0 µm, cylindric clavate, bearing two short sterigmata, soon collapsing especially towards the apex. Hymenophoral trama regular, broad, hyaline, not gelatinized, of parallel, hyaline hyphae, 2-8 µm diam. Subhymenial layer very narrow, interwoven. Peridiopellis a repent epicutis, 20-40µm thick, of parallel, hyaline hyphae, 3-6µm diam., with a slightly thickened wall. Figs. 30 A-C, 31 G-Q.

Hitherto known only from New Zealand, this species is easily recognized by the small size and cuboid spores. Many of the spores are truly cuboid i.e. Type IX (Pegler & Young 1979b: 298), isodiametric, with six quadrangular facets forming a dihedral base, and a single adaxial and abaxial facet, together with a dihedral pair of lateral facets. However, the majority of the spores are of the Dihedral Base type (Type X) in which the cube is truncated by an extra apico-adaxial facet. The species has only been found once in Victoria, occurring scattered, in small clusters.

Holotype (PDD 8385): 'On ground; Titirangi Range., Auckland; leg. Hodgkins'. - Herb. HK. ZT 68/235: 'In soil along a bank-side, track from Taylorville to Mt. Sewell, Westcoast, N.Z.; leg. Horak, 31.III.1968'.

Carpophores 3-24 mm diam., globose or irregularly tuberiform, folded near the base, pure white, turning pallid cream or ochraceous, smooth, dry, peridium covering the gleba but in old specimen leaving the gleba occasionally exposed. Gleba irregularly labyrinthiform, loculi not radially arranged, cells up to 2 mm diam., columella absent or only rudimentary, vivid pink, later becoming pallid ferruginous, not gelatinous. Stipe absent or present, short cylindrical, concolorous with peridium, without rhizoids. Odor and taste not distinctive. Chemical reactions on peridium: KOH, HCl or NH₃ - negative.
Spores 9-12 x 7-10 µm, rhomboid or 5-angled, pink, smooth. Basidia 26-35 x 10-11 µm, 4-spored. Cystidia none. Cuticle a cutis of short cylindrical, densely interwoven, hyaline hyphae (5-10 µm diam.), membrane thin-walled, not gelatinized. Clamp connections absent.

On ground among litter of Dicksonia sp., Carpodetus serratus, Ouintinia sp., etc. New Zealand.

From the taxonomical point of view Richoniella pumila represents a very interesting species with highly reduced macroscopical characters. The tuberiform gastrocarp (pileus) rarely exposes the loculate gleba (lamellae) and a fragile stipe may be observed only occasionally. The microscopical characters of Richoniella do not differ widely from those of Entoloma (Fr.) or Rhodogaster Hk., another secotioid genus, linking Richoniella with Entoloma (Fr.).