Dermoloma aff. pruinosipes

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 aff. pruinosipes

Figs 43 b , 45

Description.

Pileus 5–9 mm; convex to plano-convex, rarely broadly umbonate; margin when fresh striate to 1 / 3 to 1 / 2 of the cap (not distinctly); surface smooth, almost velvety, hygrophanous; color dark brown in center (7 F 6), towards margin usually lighter, yellowish brown (5 E 6). Stipe 15–40 × 1–2 mm; cylindrical, flexuous; surface smooth or usually white pruinose, especially at apex, sometimes finely longitudinally striate; color at apex usually grayish brown (7 E 3), often concolorous throughout but sometimes dark brown towards the base (7 F 5), with white basal mycelium. Lamellae L = 11–18, l = 1–3; 1–3 mm wide; adnexed to adnate-emarginate; color similar when young and mature, olive brown (4 E 3); edges entire. Context elastic to fragile; odor slightly farinaceous.

Spores (5.1 –) 5.7–6.1 – 6.4 (– 6.7) × (3.5 –) 3.7–3.9 – 4 (– 4.3) μm; narrowly ellipsoid or oblong, Q = (1.38 –) 1.48–1.57 – 1.65 (– 1.72); walls amyloid; hilar appendage 0.5–1 μm long. Basidia (19 –) 22–24.7 – 28 (– 30) × (5.5 –) 6–6.2 – 7 μm; clavate; with 4 sterigmata. Basidioles first cylindrical, then clavate, ca. 3.5–8 μm wide. Marginal cells (9 –) 12–16.7 – 21.5 (– 27) × (3.5 –) 4–4.9 – 6 (– 6.5) μm; not well-differentiated and similar to basidioles, cylindrical or clavate, occasionally also fusiform or lageniform. Pileipellis 45–50 μm deep; suprapellis 27–33 μm deep, usually of one layer of inflated and relatively loose cells; subpellis hardly differentiated, ca. 12–23 μm deep, of densely packed, mainly horizontally oriented, 3–10 (– 15) μm wide hyphae, gradually passing to horizontally oriented and intricate hyphae in trama; hyphal terminations with brownish yellow parietal pigments, in subpellis darker yellow-brown and sometimes slightly incrusted pigments, walls of terminal cells thickened up to 0.5 μm, in subpellis up to 1 μm. Terminal cells near pileus margin (22 –) 26.5–34.4 – 42.5 (– 50) × (11 –) 14–17.7 – 21.5 (– 25) μm; usually obpyriform, clavate, occasionally sphaeropedunculate, occasionally lobate near septa; subterminal cells mainly branched, fusiform or cylindrical, usually not inflated, occasionally lobate. Terminal cells near pileus center (24 –) 31.5–38.3 – 45 (– 52) × (11 –) 14–17.1 – 20.5 (– 28) μm; clavate, obpyriform or sphaeropedunculate; subterminal cells similar to cells near margin. Caulocystidia (26 –) 33.5–53.5 – 61 (– 85) × (4 –) 4.5–6.6 – 8.5 (– 12) μm; clavate or subcylindrical, occasionally fusiform, usually flexuous or twisted, sometimes slightly moniliform, occasionally nodulose or lobate, repent or ascending, individual or in small to larger clusters, often intermingled; thin-walled, near septa often slightly thickened up to 0.5 μm, with brownish yellow parietal pigments. Clamp connections present.

Distribution and ecology.

Known from a single locality in Austria.

Material studied.

Austria • Steiermark, Leibnitz, Heimschuh, Fastlkogel, Plesch , elev. 396 m, coord. 46°47'07"N, 15°28'51"E, semi-dry grassland, soil among mosses and grass, 15 Nov 2018, G. Friebes GF 20180313 ( SAV F-23429 ) .

Notes.

This collection is not described formally as a new species because it is represented by a single sample. It probably represents a well-defined species with amyloid spores belonging to D. subgenus Amylospora , section Atrobrunnea . It is well-supported by the multilocus phylogeny (Fig. 2 ) as closely related to D. pruinosipes and D. curvicystidiatum . It differs from both of these by the smaller basidiomata and poorly differentiated marginal cells (see above). Its delimitation from other species with small basidiomata requires more observations to understand the variability of its morphological characters.

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 43. Basidiomata of Dermoloma in field appearance. a Dermoloma pruinosipes (GLM-F 137757), photo A. Karich; b Dermoloma aff. pruinosipes, (SAV F- 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 (SAV F- 20811, holotype), photo S. Jančovičová; f Dermoloma rostratum (SAV F- 20817), photo S. Jančovičová. Scale bar: 10 mm.

Figure 45. Dermoloma aff. pruinosipes (SAV F- 23429), microscopic elements. a Spores; b caulocystidia; c basidia and basidioles; d pileipellis elements near the pileus margin; e pileipellis elements near the pileus center. Scale bar: 5 µm for spores and 10 µm for other elements.