Dermoloma angustisporum Jančovič. & Karich, 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 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.

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).

Figures

Figure 2. Phylogram generated by ML analysis based on combined sequence data of ITS, LSU, rpb 1, rpb 2, mcm 7 and tef 1 a showing phylogenetic relationships within genus Dermoloma. ML bootstrap support values greater or equal to 50 % and Bayesian posterior probabilities greater or equal to 0.90 are indicated above or below the nodes. Sequences originating from type collections are labelled in red and bold.

Figure 10. Basidiomata of Dermoloma in field appearance. a Dermoloma angustisporum (SAV F- 20343, holotype), photo S. Jančovičová; b, c Dermoloma appalachianum (TENN-F- 076604), photo D. Grootmyers; d Dermoloma applanatum (SAV F- 4415, holotype), photo D. Harries; e Dermoloma applanatum (SAV F- 4419), photo D. Harries; f Dermoloma atrocinereum [BBF (GC 16112316)], photo G. Corriol; g Dermoloma atrocinereum (SAV F- 20523), photo S. Jančovičová. Scale bar: 10 mm.

Figure 11. 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.