A phylogenetic and morphological study of the genus Dermoloma (Agaricales, Tricholomataceae) in Europe and North America exposes inefficiency of opportunistic species descriptions Author Adamčíková, Katarína 0000-0001-5407-5233 Department of Plant Pathology and Mycology, Institute of Forest Ecology, Slovak Academy of Sciences Zvolen, Akademická 2, 949 01 Nitra, Slovakia Author Kiran, Munazza 0000-0002-3671-9039 Laboratory of Molecular Ecology and Mycology, Institute of Botany, Plant Science and Biodiversity Center, Slovak Academy of Sciences, Dúbravská cesta 9, 845 23 Bratislava, Slovakia & Department of Botany, Division of Science & Technology, University of Education, Lahore, Pakistan Author Caboň, Miroslav 0000-0002-2255-3816 Laboratory of Molecular Ecology and Mycology, Institute of Botany, Plant Science and Biodiversity Center, Slovak Academy of Sciences, Dúbravská cesta 9, 845 23 Bratislava, Slovakia Author Matheny, Brandon P. 0000-0003-3857-2189 Department of Ecology and Evolutionary Biology, University of Tennessee, Knoxville, Tennessee, USA Author Sánchez-García, Marisol 0000-0002-0635-6281 Department of Forest Mycology and Plant Pathology, Swedish University of Agricultural Sciences, Box 7026, 750 07 Uppsala, Sweden Author Arnolds, Eef Department of Forest Ecology, Wageningen University, P. O. Box 9101, 6700 HB Wageningen, Netherlands Author Caboňová, Michaela 0000-0002-2207-6183 Laboratory of Molecular Ecology and Mycology, Institute of Botany, Plant Science and Biodiversity Center, Slovak Academy of Sciences, Dúbravská cesta 9, 845 23 Bratislava, Slovakia Author Corriol, Gilles https://orcid.org/0009-0008-7456-9175 Conservatoire botanique national des Pyrénées et de Midi-Pyrénées, Vallon de Salut. B. P. 315, 65203, Bagnères-de-Bigorre Cedex, France Author Dima, Bálint 0000-0003-2099-3903 Department of Plant Anatomy, Institute of Biology, Eötvös Loránd University, Pázmány Péter sétány 1 / C, H- 1117 Budapest, Hungary Author Friebes, Gernot 0000-0002-0996-3634 Studienzentrum Naturkunde, Universalmuseum Joanneum, Weinzöttlstraße 16, 8045 Graz, Austria Author Griffith, Gareth W. 0000-0001-6914-3745 Department of Life Sciences, Pont Cledwyn, Aberystwyth University, Aberystwyth SY 23 3 DD, Wales, UK Author Grootmyers, Django 0000-0002-1042-4902 Department of Ecology and Evolutionary Biology, University of Tennessee, Knoxville, Tennessee, USA Author Harries, David 0000-0002-5477-0938 Somerton Cottage, Hundleton, Pembroke, Wales, UK Author Karich, Alexander https://orcid.org/0009-0005-9295-4163 Technische Universität Dresden - Internationales Hochschulinstitut Zittau, Markt 23, 02763 Zittau, Germany Author Mešić, Armin 0000-0002-4479-600X Laboratory for Biological Diversity, Ruđer Bošković Institute, Bijenička cesta 54, HR- 10000 Zagreb, Croatia Author Mihaljevič, Martin 0000-0002-4875-9345 Institute of Geochemistry, Mineralogy and Mineral Resources, Faculty of Science, Charles University, Prague 2, Albertov 6, Czech Republic Author Moreau, Pierre-Arthur 0000-0003-4783-3643 Laboratoire de Génie Civil et géo-Environnement, University of Lille, ULR 4515 – LGCgE, 3 rue du Pr Laguesse, F- 59000 Lille, France Author Pošta, Ana 0000-0003-1715-1609 Laboratory for Biological Diversity, Ruđer Bošković Institute, Bijenička cesta 54, HR- 10000 Zagreb, Croatia Author Shapkin, Vasilii 0000-0002-8394-3009 Laboratory of Molecular Ecology and Mycology, Institute of Botany, Plant Science and Biodiversity Center, Slovak Academy of Sciences, Dúbravská cesta 9, 845 23 Bratislava, Slovakia Author Tkalčec, Zdenko 0000-0002-1148-9425 Laboratory for Biological Diversity, Ruđer Bošković Institute, Bijenička cesta 54, HR- 10000 Zagreb, Croatia Author Vizzini, Alfredo 0000-0001-8390-6446 Department of Life Sciences and Systems Biology, University of Torino, Vale P. A. Mattioli 25, 10125 Torino, Italy Author Vondrovicová, Lenka 0000-0003-2791-3160 Institute of Geochemistry, Mineralogy and Mineral Resources, Faculty of Science, Charles University, Prague 2, Albertov 6, Czech Republic Author Adamčík, Slavomir 0000-0003-2156-5767 Laboratory of Molecular Ecology and Mycology, Institute of Botany, Plant Science and Biodiversity Center, Slovak Academy of Sciences, Dúbravská cesta 9, 845 23 Bratislava, Slovakia & Department of Botany, Faculty of Natural Sciences, Comenius University Bratislava, Révová 39, 811 02 Bratislava, Slovakia Author Jančovičová, Soňa 0000-0002-9959-3314 Department of Botany, Faculty of Natural Sciences, Comenius University Bratislava, Révová 39, 811 02 Bratislava, Slovakia text IMA Fungus 2025 2025-07-10 16 e 157337 e 157337 journal article 310963 10.3897/imafungus.16.157337 94e787cd-c3e5-400f-ad11-19727fbfa928 Dermoloma angustisporum Jančovič. & Karich , sp. nov. Figs 10 a , 11 Holotype . Sweden • Medelpad , Börgsjö , Talja Gården , terrestrial on semi-natural, mown meadow , 27 Aug 2018 , J. M. Traba-Velay ( SAV F-20343 ). Etymology. With narrow spores compared to other Dermoloma species. Diagnosis. European species; basidiomata small and slender; lamellae pale yellowish white to brownish gray; spores amyloid and narrow, Q> 1.7. Pileus (7 –) 9–20 mm ; convex, soon expanding to plane, sometimes indistinctly umbonate; margin indistinctly translucently striate when wet, when dry radially cracked; surface smooth, pruinose, hygrophanous; color near margin dark brown (6 F 4), brown (6 E 4) to light brown (5 D 4), when dry grayish brown (5 D 3), brownish ochraceous (5 C 3) to ochraeous-gray (5 C 2, 6 C 2), near center dark brown (6 F 4, 7 F 4) to brown (6 E 4), when dry light brown (5 E 4,5E 5), grayish brown (5 E 3) to light brown (5 D 4). Stipe 21–32 (– 37) × 1–1.5 mm ; cylindrical, sometimes narrowed towards the base, flexuous; surface finely longitudinally striate, pruinose near lamellae, finely fibrillose towards the base; color near lamellae brownish gray (5 C 3, 5 D 3), near the base grayish brown (6 E 3), brown (6 E 4) to dark brown (6 F 3). Lamellae L = 21–28, l = 0–3; 1.5–3 mm wide; adnate-emarginate and decurrent with tooth; color yellowish white (4 A 2), ochraeous-gray (5 B 2) to brownish gray (5 C 2); edges entire or slightly irregular, rarely serrulate. Context fragile; odor weakly farinaceous. Dermoloma angustisporum ( SAV F-20343 , holotype), microscopic elements. a Spores; b caulocystidia; c basidia and basidioles; d marginal cells; e pileipellis elements near the pileus margin; f pileipellis elements near the pileus center. Scale bar: 5 µm for spores and 10 µm for other elements. Spores (5.1 –) 5.4–5.8 – 6.2 (– 6.8) × (2.9 –) 3.2–3.4 – 3.6 (– 3.9) μm; narrowly ellipsoid, oblong or narrowly amygdaloid, Q = (1.49 –) 1.60–1.70 – 1.80 (– 1.91); walls amyloid; hilar appendage 0.5–1 μm long. Basidia (22 –) 25–28.1 – 31 (– 34) × (5 –) 5.5–6.2 – 6.5 (– 7.5) μm; clavate; with 4 sterigmata. Basidioles first cylindrical, then clavate, ca. 3–6 μm wide. Marginal cells (10 –) 12.5–20.4 – 28 (– 40) × (3 –) 4–5.1 – 6.5 (– 7.5) μm; cylindrical or clavate, apically mainly obtuse or occasionally constricted, flexuous, occasionally nodulose lobate. Pileipellis 55–70 μm deep; suprapellis 35–45 μm deep, usually of one, rarely two layers of inflated, densely arranged, with some irregularly protruded terminal cells at surface; subpellis well differentiated, 20–30 μm deep, of densely packed, mainly horizontally oriented, 3–15 μm wide hyphae, gradually passing to horizontally oriented and intricate hyphae in trama; hyphal terminations with brownish parietal pigments, in subpellis darker yellow-brown pigments, walls of terminal cells thickened up to 1 μm, in subpellis up to 1.5 μm. Terminal cells near pileus margin (18 –) 28–34.9 – 42 (– 50) × (10 –) 13–15.7 – 18.5 (– 22) μm; usually obpyriform, clavate, occasionally hourglass-shaped or subcylindrical, occasionally lobate near septa; subterminal cells mainly branched, fusiform or clavate, rarely cylindrical, often lobate, with lateral swellings or projections. Terminal cells near pileus center (18 –) 26.5–35.8 – 45 (– 65) × (5 –) 10–15.1 – 20.5 (– 30) μm; clavate or obpyriform, less frequently lobate; subterminal cells narrower or equally wide, cylindrical, clavate or fusiform, occasionally branched, flexuous, occasionally with lateral swellings or nodulose. Caulocystidia (21 –) 34.5–53.5 – 72.5 (– 93) × (3 –) 3.5–5.1 – 6.5 (– 14) μm; clavate or subcylindrical, usually flexuous or twisted, often nodulose or lobate, repent and in small or larger clusters, often intermingled; usually with slightly thickened walls up to 0.5 μm, with yellowish parietal pigments. Clamp connections present. Distribution and ecology. Known from two localities; one in Germany and the type locality in Sweden (two collections); in semi-natural grassland, perhaps preferring neutral to alkaline, loamy soil, but insufficiently known. Additional material studied. Germany • Zittau , Kaiserfelder , coord. 50°52'26"N , 14°47'35"E , 16 Oct 2019 , extensive sheep-grazed pasture, with loamy soil , A. Karich and R. Ullrich IHI- 19 Der 01 ( GLM-F 137761 , as D. josserandii var. phaeopodium ) . Sweden • Medelpad , Börgsjö , Talja Gården , terrestrial on meadow , 27 Aug 2018 , S. Adamčík ( SAV F-20342 ). Notes. Dermoloma angustisporum is a member of D. subgenus Amylospora , section Atrobrunnea . The narrow spores (Q = 1.6–1.8) make it morphologically distinct from other species with similar small mycenoid basidiomata. In the phylogeny it forms a distinct clade with D. applanatum (Fig. 2 ), a species with similar spores but with much larger collybioid basidiomata (see below).