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 Corriol & Jancovic. Corriol & Jancovic. 2025 Agaricomycetes Tricholomataceae Dermoloma Fungi Agaricales Basidiomycota species pruinosipes sp. nov.   Figs 39 e, f, 43 a, 44   Etymology. In reference to the distinctly pruinose stipe.    Holotype.   Slovakia• Kremnické vrchy Mts., pasture 0.5 kmW of Tajov, elev.  600 m, coord.  48°44'54"N, 19°03'31"E, terrestrial,  25 Oct 2020, S. Jančovičová(  SAVF-20834).   Diagnosis. European species; basidiomata small, mycenoid or collybioid; pilei 9–20 mm, when wet translucently striate near margin and brown to dark brown, when dry light brown; stipes 1–3 mmwide, when young entirely pruinose; lamellae brownish ochraceous, brownish gray or grayish brown; spores amyloid, 6–7.1 × 3.9–4.4 μm; marginal cells lageniform, with long, narrow, flexuous, nodulose or diverticulate apical projections; caulocystidia, 5–18 μm wide, very variable in shape and size and often flexuous.   Figure 43. Basidiomata of  Dermolomain field appearance. a  Dermoloma pruinosipes( GLM-F 137757), photo A. Karich; b  Dermolomaaff. pruinosipes, (  SAVF-23429), photo G. Friebes; c  Dermoloma pseudojosserandii[BBF ( CH 17100504)], holotype, photo C. Hannoire; d  Dermoloma pseudojosserandii[BBF ( GC 17092306)], photo G. Corriol; e  Dermoloma rostratum(  SAVF-20811, holotype), photo S. Jančovičová; f  Dermoloma rostratum(  SAVF-20817), photo S. Jančovičová. Scale bar: 10 mm.   Figure 44.   Dermoloma pruinosipes(  SAVF-20230), 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.  Pileus(7 –) 9–20 (– 30) mm; convex, later plano-convex, sometimes indistinctly umbonate or broadly conical; margin translucently striate to half of the radius when wet; surface smooth near margin, usually radially rugulose or rough near center, hygrophanous and starting to discolor from center; color when young dark brown (6 F 4, 6 F 5), when mature near margin dark brown (6 F 4, 6 F 5, 6 F 6), sometimes grayish brown (6 D 3), when dry light brown (5 D 4), brownish ochraceous (5 C 3, 5 C 4, 6 C 4), grayish brown (5 D 3), grayish ochraceous (5 B 4), near center dark brown (6 F 4, 6 F 6, 7 F 3), rarely brown (6 E 4), when dry brown (6 E 6), light brown (5 D 5, 5 D 4), grayish brown (5 D 3), brownish ochraceous (6 C 4). Stipe(22 –) 25–40 (– 50) × 1–3 (– 4) mm; cylindrical, narrowed towards the base, flexuous; surface finely longitudinally striate, first entirely pruinose, then pruinose near lamellae, towards the base glabrous and shiny; color near lamellae brownish ochraceous (5 C 3, 6 C 3, 6 C 4), brownish gray (5 D 2), grayish brown (5 D 3, 6 D 3,6E3) to brown (6 E 4), near the base light brown (6 D 4), grayish brown (6 E 3), brown (6 E 4), dark brown (6 F 3, 6 F 4, 6 F 5, 7 F 4) LamellaeL = (13 –) 17–28, l = (0 –) 1–3 (– 5); 2.5–4 mmwide; adnexed or adnate-emarginate; color ochraceous-gray (5 B 2), brownish ochraceous (5 C 4, 6 C 4), brownish gray (6 C 2, 6 D 2), grayish brown (6 D 3); edges entire. Contextelastic to fragile; odor indistinct.  Spores(5.2 –) 6–6.5 – 7.1 (– 8) × (3.6 –) 3.9–4.1 – 4.4 (– 5) μm; narrowly ellipsoid to oblong, Q = (1.32 –) 1.45–1.59 – 1.72 (– 2.00); walls amyloid; hilar appendage 0.5–1 μm long. Basidia(20 –) 26–29.2 – 32 (– 34) × (5.5 –) 6.5–7 – 7.5 (– 9) μm; clavate; with 4 sterigmata. Basidiolesfirst cylindrical, then clavate, ca. 3–6 μm wide. Marginal cells(18 –) 21.5–28.5 – 35.5 (– 53) × (3.5 –) 4–5 – 6 (– 8.5) μm; lageniform, with long, narrow, flexuous, nodulose or diverticulate apical projections. Pileipellis48–60 μm deep; suprapellis 28–35 μm deep, usually of one or three layers of inflated, densely arranged cells; subpellis well-differentiated, 20–30 μm deep, of densely packed, puzzled, 2.5–10 μm wide hyphae, gradually passing to horizontally oriented hyphae in trama; hyphal terminations with brownish yellow parietal pigments, in subpellis near center also with incrusted brownish yellow pigments, walls thickened up to 0.5 μm, in subpellis up to 1.5 μm. Terminal cells near pileus margin (18 –) 28.5–37.7 – 47 (– 67) × (10 –) 13.5–18.8 – 24 (– 35) μm; usually obpyriform, sphaeropedunculate or clavate; subterminal cells usually unbranched, fusiform or clavate and ventricose, rarely cylindrical, often with lateral swellings or branches. Terminal cells near pileus center (20 –) 27.5–38.3 – 49 (– 72) × (7 –) 13.5–19.1 – 24.5 (– 42) μm; similar to cells near margin; subterminal cells usually narrower, narrowly fusiform. Caulocystidia(15 –) 18.5–26.8 – 35 (– 48) × 5–11.5 – 18 (– 42) μm; very variable in shape and size, some small and clavate, others large and obpyriform, sphaeropedunculate, often flexuous, sometime with projections or lobate, repent and in small or larger clusters, often intermingled, subterminal cells often with lateral projections or branches; usually with slightly thickened walls up to 0.5 μm, but near septa and on subterminal cells up to 1 μm, with brownish yellow parietal pigments. Clamp connectionspresent.   Distribution and ecology. Known from Austria, Croatia, Germany, The Netherlands, Norwayand Slovakia; in semi-natural grasslands on calcareous soil.   Additional material studied.   Austria• Burgenland, Oberwart, Rechnitz, Galgenberg, elev.  344 m, coord.  47°17'52"N, 16°25'09"E, semi-dry grassland, soil among moss and grass,  17 Nov 2019, G. Friebes GF 20190130(  SAVF-23423).  Croatia• Kamenjak peninsula,  3.5 kmS-SE of Premantura, near Pula, coord.  44°46'17"N, 13°55'06"E, grassland with  Rosmarinussp.,  20 Nov 2005, M. Čerkez( CNF 1/3789).  France• Hautes-Pyrénées, Arrens-Marsous, Caytivère, coord.  42°58'51"N, 00°14'53"E, acidophilic mountain grazed grassland(  Nardion),  4 Oct 2016, C. Hannoire CH 16100418( BBF, as   D. phaeopodium); •  Hautes-Pyrénées, Campan, vallon du Garet, coord.  42°55'06"N, 00°12'35"E, neutrophilous mountain grassland,  8 Oct 2016, G. Corriol GC 16100816( BBF, as   D. pseudocuneifolium var. obscurum); •  Puy-de-Dôme, Orcines, Puy de la Charité, coord.  45°46'17"N, 03°01'42"E, lawn on volcanic soil ( Koelerio-Phleion),  16 Oct 1999, G. Corriol GC 99101603( BBF, as   D. phaeopodium).  Germany• Altranft, Hütelandschaft, coord.  52°45'19"N, 14°03'42"E, on loamy alkaline soil in extensively grazed (sheep) semi-natural grassland,  6 Nov 2022, A. Karich, R. Ullrichand R. Jarling IHI- 22 Der 05( GLM-F 137757); •  Baden-Württemberg, Justingen, Schachenheide, coord.  48°24'35"N, 09°40'25"E, terrestrial in semi-natural grassland,  2 Oct 2021, S. Adamčík(  SAVF-20894); • ibid.,  3 Oct 2021, S. Adamčík(  SAVF-20914).  The Netherlands• Beilen, nature area Schepping, in poor grassland on calcareous loam,  1 Oct 2004, E. Arnolds Arnolds 04-110( L, as   D. rancidumn. prov.).  Norway• Akershus, Jevnaker, Rustad, semi-natural, calcareous grassland,  16 Aug 2023, T. E. Brandrud TEB 332-23( O).  Slovakia• Kremnické vrchy Mts., pasture 0.5 kmW of Tajov, elev.  600 m, coord.  48°44'54"N, 19°03'31"E, terrestrial,  24 Oct 2020, S. Adamčík(  SAVF-20815); • ibid.,  25 Oct 2020, M. Caboň(  SAVF-20845); •  Poloniny Mts.,  4 kmN of Stakčín, pastures above the water reservoir Stariná, elev.  380–420 m, coord. 49°02'431"N, 22°14'56"E, terrestrial,  25 Sep 2017, S. Adamčík(  SAVF-20230).   Notes.   Dermoloma pruinosipesis a member of D. subgenus Amylospora, section  Atrobrunnea. It belongs to an inclusive clade of species with mainly collyboid basidiomata, all of which are morphologically similar. For more comments and recommendations, see the notes under the previous species. Compared to other members of the clade it is relatively distinct, as the stipes are typically distinctly pruinose along their entire length and the marginal cells have long attenuated apical projections. The species cluster of  D. pruinosipesincludes 14 samples from seven countries, but it was represented only by a single sample in the previous phylogeny by Sánchez-García et al. (2021)and labelled as “  Dermolomasp. 8”. It is represented here by three distinct sequence variants in the ITStree (Suppl. material 8), but the multilocus phylogeny (Fig. 2) did not support to distinguish them as three separate taxa and we did not find distinct morphological differences to distinguish them. 5211959504 terrestrial 2020-10-25 SAV S. Jancovicova Slovakia Kremnicke vrchy Mts. 600 48.748333 pasture 0.5 km W of Tajov 18 19.05861 SAV F-20834 1 holotype 5211959438 semi-dry grassland, soil among moss and grass 2019-11-17 SAV G. Friebes Austria Oberwart 344 47.29778 Galgenberg 18 16.419167 Rechnitz SAV F-23423 1 Burgenland 5211959406 grassland with Rosmarinus sp. 2005-11-20 CNF M. Cerkez Croatia Kamenjak peninsula 44.77139 near Pula 19 13.918334 Premantura CNF 1/3789 1 5211959361 acidophilic mountain grazed grassland 2016-10-04 BBF Nardion & C. Hannoire France Hautes-Pyrenees 42.980835 Caytivere 19 0.24805556 Arrens-Marsous 1 5211959418 neutrophilous mountain grassland 2016-10-08 BBF G. Corriol Switzerland Hautes-Pyrenees 42.918335 vallon du Garet 19 0.20972222 Campan 1 5211959474 lawn on volcanic soil (Koelerio-Phleion) 1999-10-16 BBF G. Corriol Germany Puy-de-Dome 45.77139 Puy de la Charite 18 3.0283334 Orcines 1 5211959331 on loamy alkaline soil in extensively grazed (sheep) semi-natural grassland 2022-11-06 A. Karich & R. Ullrich & R. Jarling Germany 52.75528 Hutelandschaft 17 14.0616665 Altranft GLM-F 137757 1 5211959505 terrestrial in semi-natural grassland 2021-10-02 SAV S. Adamcik Germany 48.409725 Schachenheide 18 9.673612 Justingen SAV F-20894 1 Baden-Wurttemberg 5211959302 terrestrial in semi-natural grassland 2021-10-03 SAV S. Adamcik Netherlands 48.409725 Justingen 18 9.673612 Schachenheide SAV F-20914 1 Baden-Wuerttemberg 5211959556 in poor grassland on calcareous loam 2004-10-01 L E. Arnolds Arnolds Netherlands nature area Schepping Beilen 1 5211959337 semi-natural, calcareous grassland 2023-08-16 O T. E. Brandrud Norway Rustad Jevnaker 1 Akershus 5211959423 terrestrial 2020-10-24 SAV S. Adamcik Slovakia Kremnicke vrchy Mts. 600 48.748333 pasture 0.5 km W of Tajov 18 19.05861 Mts. SAV F-20815 1 Akershus 5211959428 terrestrial 2020-10-25 SAV M. Cabon Slovakia Kremnicke vrchy Mts. 600 48.748333 Kremnicke 18 19.05861 Mts. SAV F-20845 1 Akershus 5211959379 terrestrial 2017-09-25 SAV S. Adamcik Slovakia Poloniny Mts. 400 pastures above the water reservoir Starina 22.24889 Stakcin SAV F-20230 1 Akershus