Dermoloma fusipes Arnolds & Harries, 2025

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, 2025, A phylogenetic and morphological study of the genus Dermoloma (Agaricales, Tricholomataceae) in Europe and North America exposes inefficiency of opportunistic species descriptions, IMA Fungus 16, pp. e 157337-e 157337 : e157337-

Dermoloma fusipes Arnolds & Harries sp. nov.

Figs 27 a, b , 28

Etymology.

The stipes of mature basidiomata are distinctly fusiform.

Holotype.

United Kingdom • Wales, Powis Castle gardens , coord. 52°38'58"N, 03°09'34"E, terrestrial in lawn, 22 Oct 2014, D. Harries ( SAV F-4377 ).

Diagnosis.

European species; basidiomata relatively large; pilei 23–37 mm in diameter, not hygrophanous; stipes 3.5–7.5 mm wide, fusiform and narrowed at bases; spores inamyloid, on average narrower than 4 μm.

Pileus (11 –) 23–37 (– 45) mm; convex, later almost plane, often indistinctly umbonate, lobate; margin not striate or translucently striate up to 10 mm; surface smooth, sometimes radially slightly rugulose or rough near center, not hygrophanous; color near margin first grayish brown (6 E 3), later light brown (5 D 4), near center dark brown (6 F 3, 6 F 4 to almost black), when old brown (5 E 4). Stipe (10 –) 20–58 (– 66) × (2 –) 3.5–7.5 (– 8) mm; cylindrical or fusiform, narrowed towards the base, usually flexuous especially near the base; surface longitudinally striate, granulose or pruinose near lamellae, fibrillose to finely squamulose towards the base; color near lamellae almost white to ochraceous-gray (5 B 2), near the base brownish ochraceous (5 C 3) to brownish gray (6 C 2), sometimes with darker fibrils on paler background. Lamellae L = (26 –) 31–41 (– 43), l = 1–3; 4–10 mm wide; adnexed or adnate-emarginate and decurrent with tooth; color ochraceous-gray (5 B 2), brownish gray (5 C 2) to brownish ochraceous (6 C 3), paler towards edges; edges entire or slightly serrulate. Context fragile; odor farinaceous.

Spores (4.5 –) 5.2–5.7 – 6.2 (– 7.2) × (2.5 –) 3.4–3.8 – 4.1 (– 4.5) μm; ellipsoid to narrowly ellipsoid, Q = (1.30 –) 1.41–1.52 – 1.64 (– 1.82); walls inamyloid; hilar appendage ca. 0.5–1.5 μm long. Basidia (19 –) 23.5–27.1 – 30.5 (– 34) × (5.5 –) 6–6.8 – 7.5 (– 8) μm; clavate; with 4 sterigmata. Basidioles first cylindrical, then clavate, ca. 3.5–7.5 μm wide. Marginal cells (11 –) 13.6–20.1 – 26.7 (– 35) × (4 –) 4.5–5.3 – 6 (– 8) μm; not well-differentiated, clavate, sometimes diverticulate or lobate, flexuous. Pileipellis 65–80 μm deep; suprapellis 40–60 μm deep, usually of two or three layers of inflated, densely arranged cells; subpellis well-differentiated, 25–35 μm deep, of densely packed, irregularly oriented, puzzled, 3–10 μm wide hyphae, gradually passing to horizontally oriented hyphae in trama; hyphal terminations with brown parietal pigments, near septa of terminal cells and on subterminal cells with dark brown incrusted pigments, walls thickened especially in subpellis up to 1 μm. Terminal cells near pileus margin (20 –) 28.5–39.5 – 50.5 (– 75) × (7 –) 12.5–17.5 – 22.5 (– 30) μm; usually obpyriform, sphaeropedunculate or clavate; subterminal cells usually inflated but smaller, lobate. Terminal cells near pileus center (18 –) 30–39.3 – 49 (– 68) × (7.5 –) 13.5–18.5 – 23.5 (– 31) μm; similar to cells near margin; subterminal cells less frequently inflated, and with more conspicuous dark brown to black incrustations than near margin. Caulocystidia (12.5 –) 22–32.7 – 43.2 (– 62.4) × (2 –) 3.5–4.7 – 6 (– 10.5) μm; cylindrical or clavate, usually not or only slightly flexuous, often clustered in small ascending fascicules, sometimes individual and repent; usually with slightly thickened walls up to 0.5 μm, sometimes with scarce yellow incrustations. Clamp connections present.

Distribution and ecology.

Known from three localities in The Netherlands, Slovakia and Wales ( United Kingdom); in semi-natural grasslands; habitat preference insufficiently known.

Additional material studied.

The Netherlands • Elsloo, along Julianakanaal , 30 Oct 1982, J. Schreurs ( L 3988083 , as D. cuneifolium var. punctipes ) . Slovakia • Bolešov, chata Gilianka , coord. 49°00'19"N, 18°08'20"E, terrestrial in semi-natural grassland, 7 Oct 2013, S. Jančovičová ( SLO 2015 ) . United Kingdom • Wales, Powis Castle gardens , coord. 52°38'58"N, 03°09'34"E, terrestrial in lawn, 22 Oct 2014, D. Harries ( SAV F-4376 ) .

Notes.

Dermoloma fusipes is a member of D. subgenus Dermoloma , section Dermoloma . It has relatively large basidiomata similar to D. cuneifolium , D. huartii and D. intermedium . The identification of species in D. section Dermoloma can be problematic and requires special attention and multisource data (see notes under D. cuneifolium ). Dermoloma fusipes was included in the phylogenetic study by Sánchez-García et al. (2021) as “ Dermoloma sp. 4 ”. Sequences from French (CL / F 04.249) and Croatian ( CLF 1/2851 ) samples were of poor quality. They may belong to this species or to D. aff. fusipes described below, but they were not used in our morphological study.

Figures

Figure 27. Basidiomata of Dermoloma in field appearance. a Dermoloma fusipes (SAV F- 4376), photo D. Harries; b Dermoloma fusipes (SAV F- 4377, holotype), photo D. Harries; c Dermoloma aff. fusipes (SAV F- 4371), photo D. Harries; d Dermoloma griseobasale (SAV F- 4723, holotype), photo S. Jančovičová; e Dermoloma griseobasale [BBF (GC 10110201)], photo G. Corriol; f Dermoloma griseobasale (CNF 5 / 287), photo A. Mešić. Scale bar: 10 mm.

Figure 28. Dermoloma fusipes (SAV F- 4377, 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.