Dermoloma intermedium Bon

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 intermedium Bon , Doc. Mycol. 9 (35): 42. 1979.

Figs 31 d – f , 34

Dermoloma alexandri Consiglio in Contu, Consiglio & Setti, Micol. Veg. Medit. 22 (2): 84. 2008. Syn.

Holotype.

France • Somme, Airaines, Warlus , deciduous forest on limestone, Cephalantero-Fagion, Oct. 1967, M. Bon 71081 ( LIP).

Epitype.

(designated here MBT 10022921): France, Pas-de-Calais, Neufchâtel-Hardelot, réserve naturelle du Mont-Saint-Frieux , coord. 50°36'39"N, 01°36'35"E, calcareous grassland, 9 Nov 2014, D. Huart and P. - A. Moreau PAM 14110905 ( LIP) .

Distinguishing characters.

European species; basidiomata usually large; pilei 20–52 mm in diameter, distinctly hygrophanous; stipes 4–10 mm wide; lamellae 32–50 near the stipe attachment, gray to brownish gray; spores inamyloid.

Pileus (13 –) 20–52 (– 65) mm; convex, later almost plane, indistinctly umbonate, rarely obtusely conical; margin usually not striate, indistinctly translucently striate to half of the radius when wet, recurved when old, when dry radially cracking; surface smooth, sometimes radially rugulose or wrinkled near center, matt, sometimes pruinose, hygrophanous; color when young dark brown (7 E 4), when mature near margin sometimes with white outline, dark brown (6 F 3, 6 F 4), brown (6 E 4), grayish brown (5 E 3, 6 D 3,6E 3), when dry brown (6 E 4), grayish brown (6 D 3,6E 3), brownish gray (5 D 2, 6 D 2), brownish ochraceous (6 C 3), near center dark brown (6 F 3, 6 F 4, 6 F 5, 6 F 7, 7 F 3, 7 F 4, 7 F 6) to black, rarely brown (6 E 5), when dry brown (5 E 3,5E 4,6E 4) to black, sometimes grayish brown (5 D 3). Stipe (20 –) 26–59 (– 80) × (3 –) 4–10 (– 13) mm; cylindrical, narrowed towards the base, usually flexuous, especially near the base; surface finely longitudinally striate, near lamellae finely granulose or pruinose, towards the base fibrillose or flocculose, with age and especially near the base silky and shiny; color near lamellae pale gray (B 1 to C 1) to almost white, sometimes brownish gray (6 C 2, 7 C 2), near the base brownish gray (5 C 2, 5 D 2,5E 2, 6 C 2, 6 D 2), grayish brown (5 D 3,6E 3), brownish ochraceous (5 C 3) or sometimes ochraceous-gray (5 B 2). Lamellae L = (28 –) 32–50 (– 52), l = (0 –) 1–3 (– 7); 5–12 mm wide; adnate-emarginate and decurrent with tooth; color gray (B 1, C 1), brownish gray (5 C 2, 6 C 2, 6 D 2); edges entire or slightly irregular, rarely serrulate. Context when young compact, later fragile; odor farinaceous.

Spores (4.8 –) 5.1–5.4 – 5.8 (– 6.3) × (3.4 –) 3.7–4 – 4.2 (– 4.8) μm; broadly ellipsoid to ellipsoid, Q = (1.15 –) 1.27–1.37 – 1.46 (– 1.62); walls inamyloid, sometimes thick-walled and dextrinoid; hilar appendage 0.7–1.3 μm long. Basidia (20 –) 23.5–26.7 – 29.7 (– 34) × (4.5 –) 6–6.4 – 7 (– 8) μm; clavate; usually with 4 sterigmata, but one collection (the type) with (1 –) 2–3 sterigmata. Basidioles first cylindrical, then clavate, ca. 3–5.5 μm wide. Marginal cells (5.5 –) 12–16.2 – 21 (– 24) × (3 –) 3.5–4.4 – 5 (– 5.5) μm; cylindrical or clavate, not well-differentiated from basidioles on lamellae sides but usually smaller. Pileipellis 60–70 μm deep; suprapellis of mainly one, occasionally two layers of inflated cells, gradually passing to 23–26 μm deep subpellis of densely packed, irregularly oriented, puzzled, 4–10 (– 15) μm wide hyphae, not sharply delimited from horizontally oriented hyphae in trama; hyphal terminations with dark brown parietal pigments, thin-walled or occasionally thickened up to 1 μm and with dark incrusted pigments especially near septa of terminal cells. Terminal cells near pileus margin (15 –) 26–35.9 – 46 (– 75) × (10 –) 14.5–20.7 – 27 (– 44) μm; usually obpyriform or clavate, sometimes sphaeropedunculate, ellipsoid or subglobose; subterminal cells usually narrower and unbranched, clavate or obpyriform, often with lateral swellings. Terminal cells near pileus center (18 –) 28.5–39 – 49.5 (– 82) × (9 –) 14.5–20.9 – 27.5 (– 47) μm; usually obpyriform, ellipsoid or subglobose, rarely irregularly utriform or clavate-lageniform; subterminal cells narrower or equally wide, often with lateral swellings or irregularly lobate. Caulocystidia (16 –) 29.5–39.3 – 49.5 (– 65) × (3.5 –) 4.5–6.1 – 8 (– 11) μm; clavate or cylindrical, 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, often with crystalline or granulose yellow incrustations. Clamp connections usually present, but absent in the type collection.

Distribution and ecology.

Widely distributed and rather frequent in Europe; in semi-natural grasslands, natural, dry “ steppe-like ” grasslands, maquis shrublands and forests on calcareous soil.

Additional material studied.

Austria • Burgenland, Galgenberg, 1.1 km E of Markt Neuhodis , elev. 336 m, coord. 47°18'01"N, 16°24'38"E, 30 Nov 2019, G. Friebes GF 20190143 ( SAV F-23425 ) ; • Burgenland, Siegendorfer Puszta, Siegendorf , elev. 172 m, coord. 47°46'40"N, 16°34'53"E, 29 Oct 2017, G. Friebes GF 20170122 ( SAV F-23424 ) ; • Steiermark, Pöllau , elev. 722 m, coord. 47°13'56"N, 15°22'18"E, 26 Oct 2014, G. Friebes GF 20140133 A ( SAV F-23428 ) . Croatia • Mljet island, Mljet National Park, 1.1 km E / E-SE of Goveđari village , coord. 42°46'54"N, 17°22'33"E, rocky footpath with maquis of Arbutus unedo , Erica arborea , Phillyrea latifolia , Pinus halepensis and Quercus ilex , 13 Nov 2010, A. Mešić ( CNF 1/6124 ) ; • Mljet island, 250 m NW / W-NW of Prožurska luka village , coord. 42°43'51"N, 17°38'44"E, among mosses, hiking trail along maquis of Arbutus unedo , Myrtus communis , Pinus halepensis and Pistacia lentiscus , 9 Nov 2009, Z. Tkalčec ( CNF 1/5693 ) ; • Mljet island, 500 m NW of Prožurska luka village , coord. 42°43'57"N, 17°38'40"E, maquis of Arbutus unedo , Myrtus communis , Pinus halepensis and Pistacia lentiscus , 9 Nov 2009, A. Mešić ( CNF 1/5713 ) ; • near Krasno village, Velebit Mt. , coord. 44°49'17"N, 15°02'01"E, pasture with young trees of Picea abies and Abies alba, on the border of Fagus sylvatica , Picea abies and Abies alba forest, 30 Sep 2006, Z. Tkalčec ( CNF 1/4218 ) ; • Zagreb, Črnomerec , coord. 42°49'58.91"N, 15°56'54.6"E, grassland, mowed twice a year, 13 Oct 2010, Z. Tkalčec ( CNF 1/6496 ) . Estonia • Saarnaki island near Hiiumaa island, 13 km SEE of Käina , elev. 5–10 m, coord. 58°48'7.7"N, 23°00'3.93"E, soil among mosses and low scattered grass, associated with Juniperus sp. , 23 Sep 2008, S. Adamčík ( SAV F-4147 ) . Finland • Åland, Finström, Bergö, Husö Biological Station , coord. 60°16'33.6"N, 19°50'34.8"E, pasture, 19 Sep 1989, J. Vauras FISAP 654-13 ( H 6034917 ) . France • Hautes-Pyrénées, Bagnères-de-Bigorre, Bizourtère , coord. 42°57'19"N, 00°05'19"E, acidophilous mountain grassland (Nardion), 8 Oct 2014, C. Hannoire CH 14100810 ( BBF, as D. fuscobrunneum ) ; • Pas-de-Calais, Neufchâtel-Hardelot, réserve naturelle du Mont-Saint-Frieux , 50°36'39"N, 01°36'35"E, calcareous grassland, 10 Nov 2014, D. Huart and P. - A. Moreau PAM 14111007 ( LIP) . Germany • Baden-Württemberg, Justingen, Schachenheide , coord. 48°24'35"N, 09°40'25"E, terrestrial in grassland, 2 Oct 2021, S. Adamčík ( SAV F-20867 ) ; • ibid., 2 Oct 2021, S. Adamčík ( SAV F-20868 ) ; • ibid., 2 Oct 2021, S. Adamčík ( SAV F-20869 ) ; • ibid., 2 Oct 2021, S. Adamčík ( SAV F-20870 ) ; • ibid., 2 Oct 2021, S. Adamčík ( SAV F-20879 ) ; • ibid., 2 Oct 2021, S. Adamčík ( SAV F-20880 ) . Hungary • Heves, Mátra Mts., Parádfürdő , coord. 47°53'37"N, 20°03'15"E, terrestrial in semi-natural grassland, 11 Nov 2022, F. Németh NF- 2022-11 - 11 - 1 ( ELTE) . Italy • Emilia-Romagna, Boscone della Mesola, Mesola (FE) , under Quercus ilex , 12 Nov 2004, G. Consiglio, M. Panchetti, R. Bolletta and C. Orlandini GC 04317 ( AMB 12794 , holotype of D. alexandri ) ; • Lazio, Ostia (RM), Tenuta presidenziale di Castelporziano , 2 Dec 2009, G. Consiglio, G. Perdisa, L. Perrone and L. Setti GC 09266 ( AMB 12795 ) . The Netherlands • Noord-Holland, Duinweide tegenover Koningshof , 2 Nov 1968, E. Kits van Waveren ( L 3988081 , as D. cuneifolium var. punctipes ) . Norway • Telemark, Bamble, Kjerrvikodden , coord. 58°59'59"N, 09°43'55"E, in calcareous, coastal semi-natural grassland, 15 Oct 2012, T. Læssøe and A. Molia NOBAS 2437-16 ( O-F-245550 ) ; • ibid., 16 Oct 2013, T. Læssøe and A. Molia NOBAS 3361-16 ( O-F-22071 ) . Romania • Vladeasa Mts., pasture 1.2 km N of Belis , elev. 1060–1085 m, coord. 46°41'47"N, 23°02'10"E, terrestrial in pasture, 1 Oct 2014, S. Adamčík ( SAV F-4303 ) ; • ibid., 5 Oct 2014, M. Caboň ( SAV F-4270 ) ; • ibid., 6 Oct 2014, S. Adamčík, ( SAV F-4305 ) . Slovakia • Laborecká vrchovina Mts., pasture 1 km NW of Vyšná Jablonka , elev. 400–450 m, coord. 49°09'31"N, 22°06'18"E, terrestrial, 21 Sep 2006, S. Adamčík ( SAV F-4137 ) . Spain • Aragon, Huesca prov., Canfranc, Río de la Canal Roya , coord. 42°46'26"N, 00°30'56"E, terrestrial on pasture, under Buxus sp. and Pinus sylvestris , 3 Oct 2022, S. Adamčík ( SAV F-22198 ) ; • ibid., 3 Oct 2022, S. Adamčík ( SAV F-22209 ) ; • ibid., 6 Oct 2022, S. Adamčík ( SAV F-22273 ) ; • ibid., 6 Oct 2022, S. Adamčík ( SAV F-22274 ) ; • ibid., 6 Oct 2022, M. Caboň ( SAV F-22275 ) . United Kingdom • Wales, Pembrokeshire Coast National Park Offices, Pembroke Dock , coord. 51°41'55"N, 04°56'12"E, amenity grassland (lawn), 8 Oct 2019, D. Harries DH 19-20 ( SAV F-23433 ) .

Notes.

Dermoloma intermedium has inamyloid spores and belongs to D. subgenus Dermoloma , section Dermoloma , a group of closely related and morphologically similar species. Its phylogenetic position within the section is not resolved (Fig. 2 ), however, it is among the species with the largest basidiomata in the genus. It is a very common species that can be easily confused with another common species, D. cuneifolium , from which it differs by the distinctly hygrophanous pilei and slightly longer spores. Identification of D. intermedium requires careful attention and we recommend combining of the use of the heat map (Fig. 4 ) with other diagrams and data available in this study (see notes under D. cuneifolium ). This species was included in the phylogenetic study by Sánchez-García et al. (2021) as D. alexandri . Here we assign the older name D. intermedium to it, based on the morphology of the type, because the holotype sequencing was not successful. It was originally described from France and defined as a species with large pilei (50–80 mm in diam.) and a depressed center, inamyloid spores and broadly adnate to decurrent lamellae ( Bon 1979 a). Spores from the type were on av. 5.3 × 4.1 μm in size, which fit only two species recognized in this study (Fig. 7 ). One of these, D. atrocinereum , has never been observed with a depressed pileus center. The only candidate matching the type of D. intermedium is the species previously identified as D. alexandri by a sequence from the type collection; thus, the latter name is here synonymised with D. intermedium . Our observations revealed that the pileus diameter of D. intermedium does not exceed 65 mm. However, there is no other Dermoloma species within the many samples that we examined that had larger pilei and we suspect that Bon (1979 a) described his species based on a single collection with untypically large basidiomata. Together with D. atrocinereum and D. cuneifolium , D. intermedium might be the most common and widespread species of the genus in Europe.

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 7. Density plots showing statistical differences in micromorphological characters observed in Dermoloma (D.) and Neodermoloma (N.). North American species are indicated in yellow, European species with inamyloid spores in green and European species with amyloid spores in purple. a Spore length; b spore width; c spore Q; d caulocystidia width. Average values are presented in Suppl. material 7.

Figure 31. Basidiomata of Dermoloma in field appearance. a Dermoloma huartii [LIP (PAM 14110907), holotype], photo D. Huart; b Dermoloma huartii [LIP (PAM 14110909)], photo D. Huart; c Dermoloma hygrophorus [BBF (GC 01102501)], photo G. Corriol; d Dermoloma intermedium (SAV F- 4270), photo S. Jančovičová; e Dermoloma intermedium (SAV F- 22209), photo S. Jančovičová; f Dermoloma intermedium [LIP (PAM 14110905)], epitype, photo P. - A. Moreau. Scale bar: 10 mm.

Figure 34. Dermoloma intermedium [LIP (Bon 71081), 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.