Entoloma subgriseosquamulosum J. Q. Yan, L. G. Chen & S. N. Wang 2025, sp. nov.

Entoloma subgriseosquamulosum J. Q. Yan, L. G. Chen & S. N. Wang sp. nov. Fig. 3 Etymology. Refers to its morphology similar to “ Entoloma griseosquamulosum ”. Holotype. China • Fujian Province, Wuyishan City, Yangzhuang Town, Xiyuan Village, 27.7632°N, 117.8139°E, alt. 533 m, 26 June 2022, collected by Jun-Qing Yan, Cheng-Feng Nie, and Lin-Gen Chen, HFJAU 3969. Diagnosis. Entoloma subgriseosquamulosum is mainly characterized by the rather small, collybioid basidiomata, fuscous pileus, crowded and adnate lamellae, glabrous stipe, medium-sized basidiospores with 5–6 angles, mostly 5 angles, and absence of clamp connections. It differs from E. griseosquamulosum G. M. Gates & Noordel. by its gray stipe, smaller basidiospores, and absence of brilliant granules in hyphae. Macromorphology. Basidiomata rather small, collybioid. Pileus 11–20 mm wide, campanulate to convex with slight depressed center, with entire margin, not hygrophanous, gray hairy scaly with denser center, translucently striate almost up to 1 / 2 of the radius, fuscous (4 D 2–4 F 2) to dark gray (1 F 1–4 F 1), darker at center. Lamellae relatively crowded, 2.0–4.0 mm wide, with two types of lamellulae, adnate to emarginate, ventricose, initially white, then brownish-rose, with entire and concolorous edge. Stipe 20–42 × 1.5–3.0 mm, central, terete, equal, hollow, gray (1 C 1–1 E 1), darker downwards, sparsely white fibrillous in the upper part elsewhere smooth and glabrous, base with white mycelium. Context thin, white. Odor indistinct, taste not tested. Micromorphology. Basidiospores (8.1) 8.4–10.5 (11) × (6.0) 6.5–8.0 (8.5) μm, (av = 9.3 × 7.4 μm), Q = 1.1–1.4 (1.5) (Qm = 1.3 ± 0.07, n = 100), subisodiameterical or heterodiametrical, 5–6 angles, mostly 5 angles in profile view, thick-walled, inamyloid. Basidia 27–36 × 10–13 μm, clavate, 4 - spored, sterigmata 6.0–9.0 μm long, clampless. Pleurocystidia absent. Lamellae edge sterile of poliopus-type. Cheilocystidia 27–64 × 9.0–14 μm, clavate. Lamellar trama regular, made up of cylindrical hyphae 7.0–12 µm wide. Pileipellis a trichoderm made up of cylindrical hyphae 6.0–12 μm broad, with clavate terminal elements and yellow-brown intracellular pigment. Stipitipellis a cutis composed of densely arranged, cylindrical hyphae, 7.0–17 μm wide, slightly constricted at the septa, with acute or attenuated end. Clamp connections absent. Habitat. Solitary on soil or moss in broad-leaved forest. Distribution. So far known from Fujian Province in China. Additional specimens examined. China • Fujian Province, Wuyishan City, Yangzhuang Town, Xiyuan Village, 27.7652°N, 117.8164°E, alt. 512 m, 26 June 2022, collected by Jun-Qing Yan, Cheng-Feng Nie, and Lin-Gen Chen, HFJAU 3967. Notes. Morphologically, several similar species within Entoloma subg. Cyanula that share brown to brown-gray pileus can be distinguished from the new species as follows: E. anatinum (Lasch) Donk is characterized by its larger basidiospores (9.0–13.5 × 7.5–9.0 μm) with 6–9 angles, and fertile lamellae edge (Donk 1949); E. glaucobasis Huijsman ex Noordel. has larger basidiospores (10–13.5 × 7.0–8.0 μm) (Noordeloos 1985); E. griseosquamulosum differs from the new species by the gray-violet stipe, larger basidiospores (9.0–12 × 7.0–9.0 μm), and presence of abundant brilliant granules in all hyphae (Noordeloos and Gates 2009); E. phaeomarginatum E. Horak is recognized by the fibrillose pileus, brown lamellae edge, and larger basidiospores (10–13 × 7.0–8.0 μm) (Horak 1973); E. saponicum G. M. Gates & Noordel. is distinct by the blackish brown lamellae edge and presence of abundant brilliant granules in all hyphae (Noordeloos and Gates 2009). Phylogenetically, E. cyanostipitum Xiao L. He & W. H. Peng is closest to the new species. However, E. cyanostipitum is distinct by the deep blue pileus margin, lamellae edge and stipe, and the ITS region, with an 84 % similarity (He et al. 2017).