Veg. Medit. 22 (2): 105. 2008 A phylogenetic and morphological study of the genus Dermoloma (Agaricales, Tricholomataceae) in Europe and North America exposes inefficiency of opportunistic species descriptions Adamčíková, Katarína Kiran, Munazza Caboň, Miroslav Matheny, Brandon P. Sánchez-García, Marisol Arnolds, Eef Caboňová, Michaela Corriol, Gilles Dima, Bálint Friebes, Gernot Griffith, Gareth W. Grootmyers, Django Harries, David Karich, Alexander Mešić, Armin Mihaljevič, Martin Moreau, Pierre-Arthur Pošta, Ana Shapkin, Vasilii Tkalčec, Zdenko Vizzini, Alfredo Vondrovicová, Lenka Adamčík, Slavomir Jančovičová, Soňa IMA Fungus 2025 2025-07-10 16 e 157337 e 157337 34XHN Contu Contu Agaricomycetes Tricholomataceae Dermoloma Fungi Agaricales Basidiomycota species pusillum   Fig. 47    Holotype.   Italy• Sardinia, near Olbia, Pittulongu,  19 Dec 2006, F. Bocianolo  30 - XII- 2006( AQUI).   Distinguishing characters. European species; basidiomata small, mycenoid; spores amyloid, broadly ellipsoid to narrowly ellipsoid, up to 6.5 μm long; caulocystidia large, 25.5–46 × 9.5–15.5 μm, clavate, sphaeropedunculate or obpyriform, known only from Mediterranean areas of Europe.  Basidiomatanot collected by authors of this study, for description see original description ( Contu et al. 2008).  Spores(5.4 –) 5.7–6 – 6.4 (– 6.7) × (3.7 –) 4.3–4.6 – 4.8 (– 5.3) μm; broadly ellipsoid to narrowly ellipsoid, Q = (1.19 –) 1.25–1.32 – 1.39 (– 1.51); walls amyloid; hilar appendage ca. 1–1.5 μm long. Basidia(25 –) 26.5–28.5 – 30.5 (– 34) × (5 –) 5.5–6.2 – 7 (– 8) μm; clavate, cylindrical or fusiform; with 4 sterigmata. Basidiolesfirst cylindrical, then clavate, ca. 3.5–6 μm wide. Marginal cells(10 –) 15–18.6 – 22 (– 25) × (2 –) 4–6.1 – 8.5 (– 11) μm; clavate or cylindrical, flexuous, often lobate, apically mainly obtuse but often also constricted. Pileipellis40–58 μm deep; suprapellis 30–40 μm deep, mainly of one layer of inflated, densely arranged cells; subpellis not well-differentiated, 16–20 μm deep, of densely packed, mainly horizontally oriented, intricate, branched, 2–5 (– 10) μm wide hyphae gradually passing to horizontally oriented hyphae in trama; hyphal terminations with brownish yellow parietal pigments, usually thin-walled or with slightly thickened walls up to 0.7 μm. Terminal cells near pileus margin (20 –) 29.5–38.1 – 46.5 (– 58) × (9 –) 15–19.5 – 24 (– 30) μm; mainly sphaeropedunculate, occasionally obpyriform or clavate, near septa flexuous, and sometimes nodulose; subterminal cells usually narrower and subcylindrical, occasionally clavate or fusiform, often branched or nodulose, flexuous. Terminal cells near pileus center (24 –) 33–43.3 – 54 (– 71) × (10 –) 15.5–21 – 26.5 (– 30) μm; mainly clavate, often also sphaeropedunculate, more distinctly clavate and nodulose towards septa; subterminal cells similar to cells near margin. Caulocystidia(24 –) 25.5–35.8 – 46 (– 78) × (7 –) 9.5–12.5 – 15.5 (– 20) μm; clavate, sometimes sphaeropedunculate or obpyriform, apically obtuse, repent with ascending tips or erect, often irregularly oriented, individual or in small to large fascicules; thin-walled, with brownish yellow parietal pigments. Clamp connectionspresent.   Figure 47.   Dermoloma pusillum(AQUI 30. XII. 2006, holotype), microscopic elements. aSpores; bcaulocystidia; cbasidia and basidioles; dmarginal cells; epileipellis elements near the pileus margin; fpileipellis elements near the pileus center. Scale bar: 5 µm for spores and 10 µm for other elements.   Distribution and ecology. Known only from Sardinia( Italy); possibly an exclusively Mediterranean species.   Additional material studied.   Italy• Sardinia, near Olbia, Pittulongu,  11 Jan 2008, M. Contu  11. I. 2008( AQUI).   Notes. Two collections representing the type of  D. pusillumand other authentic material were included in the study by Sánchez-García et al. (2021). The species was not collected by the authors of this study. It has amyloid spores and belongs to D. subgenus Amylospora, section  Atrobrunnea. It forms a well-supported clade with  D. obscurum,  D. clavicystisand an unclarified  Dermolomaspecies (Fig. 2; for morphological differences see notes under  D. obscurum). The most similar species is probably  D. vestigium, due to its very small basidiomata and similar spores. They differ by narrower, attenuated and flexuous marginal cells and shorter caulocystidia in the latter species. 5211959336 2006-12-19 2006-12-30 2006-12-19 AQUI F. Bocianolo Italy Pittulongu near Olbia 1 Sardinia holotype 5211959446 2008-01-11 AQUI M. Contu Italy Pittulongu near Olbia 1 Sardinia