Dermoloma phaeopodium P. D. Orton

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 phaeopodium P. D. Orton , Notes. R. bot. Gdn. Edinb. 28 (2): 327. 1980.

Figs 39 c, d , 42

Holotype.

United Kingdom • Devon, Membury, Inter graminos , 28 Oct 1977, P. D. Orton 4905 ( E 16877 ).

Distinguishing characters.

European species; basidiomata medium to small, collybioid; pilei 8–25 mm in diameter, brown to dark brown when wet and light brown when dry; stipes 1–4 mm wide, towards bases darker brown; lamellae brownish gray, brownish ochraceous or grayish brown; spores amyloid, 5.6–6.5 × 3.5–4.2 μm; marginal cells mainly clavate and apically obtuse; caulocystidia 4.5–11.5 μm wide, variable in size and shape, often flexuous or twisted.

Pileus (6 –) 8–25 (– 32) mm; convex to plano-convex, often broadly umbonate, sometimes weakly depressed or lobate; margin indistinctly translucently striate to half of the radius; surface smooth, often rugulose or rough near center, sometimes pitted, hygrophanous; color when young dark brown (7 E 4), near margin dark brown (6 F 5, 6 F 6, 6 F 7, 7 F 4, 8 F 3, 8 F 4), brown (6 E 4,6E 5), grayish brown (6 E 3), yellowish brown (5 D 5), when dry light brown (6 D 6), grayish brown (6 D 3), brownish ochraceous (6 C 3), grayish ochraceous (5 B 3, 5 B 4), near center darker or concolorous (5 E 5,6E 5,6E 7, 6 F 7, 7 F 4, 7 F 5, 7 F 6, 8 F 3) to black, when dry brown (6 E 5,6E 6), dark blond (5 D 4), brownish ochraceous (6 C 4). Stipe (20 –) 24–42 (– 46) × 1–4 (– 5) mm; cylindrical, narrowed towards the base, flexuous especially near the base; surface finely pruinose near lamellae, towards the base finely fibrillose or smooth; color near lamellae brownish ochraceous (5 C 3), grayish brown (5 D 3), dark blond (5 D 4), brownish gray (6 C 2), grayish brown (6 D 3,6E 3,7E 3), light brown (6 D 4), near the base grayish brown (6 D 3,6E 3), brown (6 E 4) to dark brown (6 F 4, 6 F 5, 7 F 4). Lamellae L = (15 –) 19–32, l = (0 –) 1–3 (– 7); 2–7 mm wide; adnexed or adnate-emarginate and decurrent with tooth; color brownish gray (6 C 2), brownish ochraceous (6 C 3), grayish brown (6 D 3,6E 3, 7 D 3,7E 3), near edges paler brownish gray (6 C 2, 7 C 2); edges entire. Context when young elastic, later fragile; odor farinaceous.

Spores (5 –) 5.6–6.1 – 6.5 (– 7.8) × (3.1 –) 3.5–3.9 – 4.2 (– 5.2) μm; ellipsoid to oblong, Q = (1.37 –) 1.46–1.57 – 1.68 (– 1.88); walls amyloid; hilar appendage ca. 0.5 μm long. Basidia (23 –) 25.5–28.3 – 31 (– 37) × (4.5 –) 5.5–6.3 – 7 (– 8) μm; clavate; with 4 sterigmata. Basidioles first cylindrical, then clavate, ca. 3–6 μm wide. Marginal cells (13 –) 16–21.1 – 26 (– 37) × (3.5 –) 4.5–6.2 – 8 (– 11) μm; clavate, occasionally cylindrical, occasionally flexuous or nodulose. Pileipellis 55–60 μm deep; suprapellis of mainly one, rarely two layers of inflated cells; subpellis well-defined, 20–25 μm deep, of densely packed, irregularly oriented, puzzled, 3–11 μm wide hyphae, not sharply delimited from horizontally oriented hyphae in trama; hyphal terminations with brownish parietal pigments, frequently with thickened walls up to 1 μm, in subpellis more thick-walled up to 1.3 μm, rarely with indistinct incrusted brownish pigments. Terminal cells near pileus margin (6.5 –) 27.5–35.5 – 43.5 (– 57) × (7.5 –) 13–18 – 23 (– 35) μm; usually clavate or sphaeropedunculate, rarely obpyriform, towards septa sometimes constricted, rarely with lateral projections; subterminal cells usually equally large or more voluminous (longer), ellipsoid or cylindrical, occasionally with lateral swellings or nodulous. Terminal cells near pileus center (11.5 –) 24.5–33.6 – 42.5 (– 60) × (7 –) 14–19.1 – 24 (– 32) μm; obpyriform, sphaeropedunculate, occasionally clavate ellipsoid or subglobose; subterminal cells narrower, equally wide or wider, cylindrical, obpyriform, ellipsoid, occasionally branched, often with lateral swellings. Caulocystidia (12 –) 22.5–32.7 – 42.5 (– 64) × (3 –) 4.5–7.9 – 11.5 (– 19) μm; very variable, clavate, fusiform, cylindrical, rarely lageniform, flexuous to curved or twisted, often moniliform, often nodulose or lobate, apically obtuse but occasionally constricted, often clustered in small ascending fascicules, sometimes individual and repent; usually with slightly thickened walls up to 0.5 μm, with brownish parietal pigments. Clamp connections present.

Distribution and ecology.

Known from Croatia, Germany, Italy, Slovakia and United Kingdom; in grasslands, preferably on alkaline soil.

Additional material studied.

Croatia • Mljet Island, Mljet National Park, 750 m SW / W-SW of Pomena village , coord. 42°47'02"N, 17°20'09"E, grassland with Cistus sp. and Olea europaea , 14 Nov 2010, A. Mešić ( CNF 1/6130 ) . Germany • Baden-Württemberg, Justingen, Schachenheide , coord. 48°24'35"N, 09°40'25"E, terrestrial in semi-natural grassland, 2 Oct 2021, S. Adamčík ( SAV F-20859 ) ; • ibid., 2 Oct 2021, S. Adamčík ( SAV F-20865 ) ; • Rheinland-Pfalz, Heimberg , elev. 265 m, coord. 49°48'37"N, 07°44'06"E, terrestrial in semi-natural grassland, 10 Nov 2019, S. Adamčík ( SAV F-20541 ) ; • ibid., 10 Nov 2019, S. Adamčík ( SAV F-20545 ) ; • ibid., 10 Nov 2019, S. Adamčík ( SAV F-20546 ) ; • ibid., 10 Nov 2019, S. Adamčík ( SAV F-20548 ) ; • Gampenstein, Hainewalde , coord. 50°55'14"N, 14°43'22"E, loamy, ancient, semi-natural grassland, 27 Sep 2022, A. Karich and R. Ullrich IHI- 22 Der 02 ( GLM-F 137755 ) . Italy • Prato, Piani et Pragho , 8 Oct 2013, F. Bocianolo G 3112 ( GDOR) . Slovakia • Zvolenská kotlina Basin, pasture E of Bečov , elev. 400–450 m, coord. 48°38'48"N, 19°14'49"E, terrestrial, 28 Aug 2014, S. Adamčík ( SAV F-4249 ) . Spain • Pyrénées Mts., Canfranc, Río de la Canal Roya , coord. 42°46'26"N, 00°30'56"E, terrestrial under Buxus sp. and Pinus sylvestris , 3 Oct 2022, S. Adamčík ( SAV F-22208 ) .

Notes.

Dermoloma phaeopodium is a member of D. subgenus Amylospora , section Atrobrunnea . It belongs to an inclusive clade of species with mainly collyboid basidiomata such as D. curvicystidiatum , D. griseobasale , D. confusum and D. pruinosipes (Fig. 2 ). In the field it is very difficult to distinguish it from other members of this clade, and it is especially similar to D. confusum (see notes under to that species). We recommend to combine the key with the heat map (Fig. 4 ) and other data available in this publication to get a better probability of correct identification, or to verify it with sequence data of the ITS region. The concept of D. phaeopodium is based on the position of the type sequence and was already recognized correctly by Sánchez-García et al. (2021).

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 4. Heatmap showing clustering based on important morphological differences in Dermoloma (D.) and Neodermoloma (N.). Characters are classified into three categories. Pdia – pileus diameter: 1 = up to 12 mm, 2 = 13–25 mm, 3 = more than 25 mm; Pstr – striation near pileus margin: 1 = none, 2 = indistinct, 3 = distinct; Phyg – pileus hygrophaneity: 1 = none, 2 = indistinct, 3 = distinct; Sthi – stipe thickness: 1 = up to 2 mm, 2 = 2–5 mm, 3 = more than 5 mm; Lnum – number of lamellae near stipe: 1 = up to 20, 2 = 21–30, 3 = more than 30; Lcol – lamellae color: 1 = white to ochraceous-gray, 2 = brownish gray to brownish ochraceous, 3 = brown to dark gray-brown; SPam – spore amyloidity: 1 = inamyloid, 3 = amyloid; SPle – spore length: 1 = up to 5.5 µm, 2 = 5.6–6.5 µm, 3 = more than 6.5 µm; SPwi – spore width: 1 = up to 3.6 µm, 2 = 3.7–4.2 µm, 3 = more than 4.2 µm; SPQ – spore length / width ratio: 1 = less than 1.4, 2 = 1.4–1.6, 3 = more than 1.6; Blen – basidia length: 1 = up to 25 µm, 2 = 26–28 µm, 3 = more than 28 µm; Bwid – basidia width: 1 = less than 6 µm, 2 = 6–6.5 µm, 3 = more than 6.5 µm; MCsh – shape of marginal cells: 1 = cylindrical or clavate and apically obtuse, 2 = lageniform and apically constricted or attenuated, 3 = lobate and diverticulate or branched; Cwid – caulocystidia width: 1 = less than 5.5 µm, 2 = 5.5–8 µm, 3 = more than 8 µm; Csha – shape of caulocystidia: 1 = cylindrical or narrowly clavate and apically obtuse, 2 = broadly clavate or sphaeropedunculate or obpyriform, 3 = lobate or diverticulate or branched.

Figure 39. Basidiomata of Dermoloma in field appearance. a Dermoloma obscurum (SAV F- 20553), photo S. Jančovičová; b Dermoloma parvisporum (SAV F- 20229, holotype), photo S. Jančovičová; c Dermoloma phaeopodium (SAV F- 20546), S. Jančovičová; d Dermoloma phaeopodium (SAV F- 22208), photo S. Jančovičová; e Dermoloma pruinosipes (SAV F- 20834, holotype), photo S. Jančovičová; f Dermoloma pruinosipes (SAV F- 20504), photo S. Jančovičová. Scale bar: 10 mm.

Figure 42. Dermoloma phaeopodium (E 16877, 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.