Dermoloma aff. bellerianum

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. bellerianum

Fig. 17

Description.

Pileus 15–45 mm; convex with more or less persistent umbo; margin not striate; surface densely radially wrinkled, not hygrophanous; color when young and fresh anthracite black, with age and when drying fading from margin, becoming pale lilac-gray with white margin. Stipe 40–70 × 3–8 (– 10) mm, cylindrical, narrowed towards the base; surface longitudinally twisted-striate, near lamellae minutely pruinose when young, then furfuraceous all along; color white, with gray fibrils. Lamellae very broad; adnate-emarginate; color white to grayish; edges entire. Context white or hyaline gray; odor strongly farinaceous.

Spores (4.9 –) 5.1–5.5 – 5.8 (– 6.2) × (2.9 –) 3.1–3.3 – 3.4 (– 3.7) μm; narrowly ellipsoid to oblong, Q = (1.55 –) 1.60–1.67 – 1.74 (– 1.84); walls inamyloid, sometimes thick-walled and dextrinoid; hilar appendage ca. 0.5–1 μm long. Basidia (19 –) 20.5–23.3 – 26 (– 30) × (4.5 –) 5–5.3 – 5.5 (– 6) μm; clavate; with 2 sterigmata, occasionally with 1 sterigma. Basidioles first cylindrical, then clavate, ca. 3–5 μm wide. Marginal cells (11.5 –) 14–16.7 – 19.5 (– 21) × 2.5–3.4 – 4 (– 5) μm; not well-differentiated and similar to basidioles, clavate or cylindrical. Pileipellis 80–105 μm deep; suprapellis 55–70 μm deep, of one to three layers of densely arranged inflated cells; subpellis 15–35 μm deep, hardly differentiated, of almost horizontally oriented, puzzled, 4–15 (– 25) μm wide hyphae, not sharply delimited from horizontally oriented hyphae in trama; hyphal terminations with brownish yellow parietal pigments, near septa of terminal cells and in subpellis often with darker brown and near center almost black incrusted pigments, terminal cells often with slightly thickened walls up to 0.5 μm, in subpellis thick-walled (walls up to 1 μm). Terminal cells near pileus margin (25 –) 34.5–46.1 – 58 (– 70) × (16 –) 19.5–24.1 – 29 (– 34) μm; obpyriform, clavate or sphaeropedunculate; subterminal cells branched or not, mainly inflated and with large lateral swellings, occasionally narrower fusiform or subcylindrical, often lobate or nodulose. Terminal cells near pileus center (27 –) 40.5–55.4 – 70 (– 95) × (13 –) 18–26.1 – 34.5 (– 49) μm; usually clavate or sphaeropedunculate, occasionally obpyriform or ellipsoid, occasionally lobate near septa; subterminal cells mainly branched, usually narrow, cylindrical or fusiform, implemented in intricate hyphae of subpellis. Caulocystidia (35 –) 41.5–51.8 – 62 (– 73) × (4.5 –) 5–6.1 – 7 (– 8.5) μm; clavate or cylindrical, usually not or only slightly flexuous, in dispersed fascicules, repent or ascending; thin-walled or occasionally with slightly thickened walls up to 0.5 μm, often with crystalline or granulose yellow incrustations. Clamp connections absent.

Distribution and ecology.

Known from a single locality in a deciduous forest in France.

Material studied.

France • Oise, Sacy-le-Grand, marais de Sacy , coord. 49°19'57"N, 02°36'08"E, thicket of Acer campestre and Corylus sp. , 29 Oct 2014, P. Clowez, F. Petit and P. - A. Moreau PAM 14102921 ( LIP) .

Notes.

Dermoloma aff. bellerianum is a well-supported member of D. section Conica and closely related but distinct from D. bellerianum . It has a very similar morphology to this species but differs from it by the wider spores (Q <1.6). We do not formally describe it as a new species because it is represented only by a single poorly documented collection. This collection came from the very same place as a typical collection of D. bellerianum (CL / F 13.170) one year later, with an extremely similar macromorphology. The presence of clampless basidia and the inamyloid, relatively narrow, ellipsoid spores (av. Q = 1.49) of D. pseudocuneifolium (based on the type) are unique for the genus, thus suggesting that D. aff. bellerianum can be identical with D. pseudocuneifolium . However, the name is well adopted in the literature and used for an amyloid Dermoloma species ( Vesterholt 2012). To avoid further confusion, we recommend to treat the name D. pseudocuneifolium as dubious.

Figures

Figure 17. Dermoloma aff. bellerianum [LIP (PAM 14102921)], 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.