Entoloma altissimum (Massee) E. Horak,
Index Fungorum number: IF 313663
Pileus 22 mm broad, conical to campanulate, not hygrophanous, not translucently striate, densely radially fibrillose, light blue to pastel blue (21A4, 21A5). Lamellae narrowly adnate, emarginate, almost concolorous with the pileus, slightly darker (21A6), with irregularly serrate concolorous edge. Stipe 70 × 4–5 mm, cylindrical, slightly broader towards the base, fistulose, longitudinally fibrillose, lighter than the pileus, pastel blue (21A3, 21A4). Context concolorous with the surface. Odour and taste indistinct. All parts of the fruitbody stain yellow to greyish yellow (3A6, 3B6) when bruised. Spores 6.5–9.1× 6.4–8.3μm, Q = 1.0–1.2, cuboid to subcuboid. Basidia 40.2–54.8 × 11.3–14.1 μm, clavate, 4-spored, clamped. Lamellae edge sterile. Cheilocystidia narrowly clavate, 56.5–100.9 × 9.9–13.6 μm, with granular intracellular pigment. Oleiferous hyphae abundant, 4–15 μm wide. Pseudocystidia present as endings of oleiferous hyphae, 25.8–43.7 × 4.2–8.5 μm, cylindrical to subcapitate, with contents yellowish brown in KOH. Pileipellis a plagiotrichoderm made up of ascending cylindrical hyphae with inflated terminal elements, 14.4–17.2 μm wide, with granular intracellular pigment. Brilliant granules abundant. Clamp connections present.
Distribution: Singapore (type), Borneo, Madagascar (as Rhodophyllus cubisporus Pat.); Vietnam.
Collection examined: Vietnam, Lam Dong Prov., Lac Duong Dist., Bidoup-Nui Ba National Park, environs of Klong Lanh, near the passing across Da Nhim riv., 12°08´09´´ N, 108°39´10´´ E, 1400 m alt., on soil in evergreen broadleaf forest, 03 July 2010, leg. A. Vasilieva, LE 262945.
Notes: A number of species characterized by the blue-green colour of the fruitbody with yellow discoloration, cuboid spores, abundant oleiferous hyphae, which sometimes protrude through the hymenium and form pseudocystidia, and brilliant granules in the trama is known from different parts of the world: E. aeruginosum Hiroë from Japan, Entoloma altissimum (Massee) E. Horak from Singapore, E. virescens (Berk. et M. A. Curtis) E. Horak ex Courtec. from Bonin Island (Horak, 1976); Rhodophyllus cubisporus Pat., Rh. holocyaneus Romagn. and Rh. psittacinus Romagn. from Madagascar (Romagnesi, 1941); E. hochstetteri (Reichardt) G. Stev. from New Zealand (Horak, 2008); E. subaltissimum T. H. Li et Chuan H. Li from China. Some of them were synonymized by Horak (1976, 1980, 2008) or were considered as E. virescens sensu lato due to the impossibility until the present day to estimate the degree of morphological variation within separate species and to establish well-defined interspecific limits. We found it possible to classify our specimen as E. altissimum through small spores and clavate cheilocystidia.