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

Entoloma subpraegracile J. Q. Yan, L. G. Chen & S. N. Wang sp. nov. Fig. 4 Etymology. Refers to its macroscopic morphology similar to “ Entoloma praegracile ” Holotype. China • Zhejiang Province, Lishui City, Qingyuan County, Bandaihoushang Village, 27.6748°N, 119.0780°E, alt. 1084 m, 7 July 2020, collected by Jun-Qing Yan and Yan-Liu Chen, HFJAU 1822. Diagnosis. Entoloma subpraegracile is mainly characterized by the yellow, glabrous, and striate pileus, white, adnexed to adnate lamellae with tiny lateral veins, 5–7 angled and medium-sized basidiospores, sterile or heterogeneous lamellae edge of serrulatum-type, cylindrical or clavate cheilocystidia, and absence of clamp connections. It differs from E. praegracile by the larger basidiomata, and sterile or heterogeneous lamellae edge. Macromorphology. Basidiomata rather small. Pileus 10–20 mm wide, conical when young, then convex to flattened with depressed, rarely cuspidate center, with entire margin, not hygrophanous, smooth and glabrous, translucently striate almost up to the center, ochre (7 B 4–6), grayish yellow (1 A 4–5) to tawny (2 C 4–6), darker at center. Lamellae relatively dense, 1.5–2.0 mm wide, with tiny lateral veins and two or three types of lamellulae, adnate to adnexed, subventricose, white, with entire and concolorous edge. Stipe 25–35 × 2.0– 2.5 mm, central, terete. equal, hollow, concolorous or paler with the pileus, smooth and glabrous, sometimes grooved, white tomentose at the base. Context thin, concolorous to the surface. Odor indistinct, taste not tested. Micromorphology. Basidiospores (7.0) 8.5–10.5 (12) × (6.0) 6.5–7.5 (8.5) μm, (av = 9.6 × 7.0 μm), Q = 1.2–1.6 (1.7) (Qm = 1.4 ± 0.08, n = 200), heterodiametrical, 5–7 (8) angles in profile view, appearing nodulose, thick-walled, inamyloid. Basidia 27–37 × 9–12 μm, clavate, slightly constricted at middle, mainly 2 - spored, sterigmata 6.0–12 μm long, clampless. Pleurocystidia absent. Lamellae edge sterile or heterogeneous of poliopus-type. Cheilocystidia dense clusters on lamellae edge, 21–53 × 7.0–14 μm, cylindrical or clavate. Lamellar trama regular, made up of cylindrical hyphae 4.0–8.0 µm wide. Pileipellis a cutis made up of cylindrical hyphae 5.0–12 μm broad, with transitions to a trichoderm towards the center with clavate terminal elements 10–16 μm wide, with tawny intracellular pigment. Stipitipellis a cutis composed of densely arranged, cylindrical hyphae, 7.0–15 μm wide, slightly constricted at the septa, with rounded end. Clamp connections absent. Habitat. Solitary or scattered on soil in mixed coniferous-broad-leaved forest. Distribution. So far known from eastern China. Additional specimens examined. China • Fujian Province, Wuyishan City, 27.8594°N, 117.9096°E, alt. 372 m, 12 August 2021, collected by Jun-Qing Yan and Ze-Wei Liu, HFJAU 3094 • 27.8563°N, 117.8661°E, alt. 668 m, 13 August 2021, collected by Qin Na, Yu-Peng Ge, and Lan-Yu Sun, HFJAU 3164, HFJAU 3168 • 27.7221°N, 117.7072°E, alt. 654 m, 16 August 2023, collected by Nian-Kai Zeng, Cheng-Feng Nie, Hua-Zhi Qin, Hui Deng, Tian Jiang, and Run-Xiang Zhao, HFJAU 5110, HFJAU 5115, HFJAU 5140, HFJAU 5175, HFJAU 5177. Notes. In the phylogenetic tree, E. subpraegracile groups together with E. praegracile. Entoloma praegracile differs from the new species by the smaller pileus (less than 10 mm), fertile lamellae edge, and the ITS sequence with 86 % similarity (He et al. 2011). Some similar species with a yellow pileus within subg. Cyanula can be distinguished from the new species as follows: E. chloropolium (Fr.) M. M. Moser is recognized by the fertile to heterogeneous lamellae edge, and septate cheilocystidia (Noordeloos 2004); E. formosum (Fr.) Noordel. is characterized by its squamulose pileus, larger basidiospores (9.0–12.5 × 6.0–8.0 μm), and fertile or heterogeneous lamellae edge (Bas et al. 1988 b). E. luteoochraceum Ribes & Vila is distinct by the squamous pileus, 4 - spored basidia, and fertile lamellae edge (Ribes and Vila 2013); E. pseudoturci Noordel. has tomentose to squamous and not striate pileus, porphyrogriseum-type lamellae edge, and brilliant granules in tissue cells (Noordeloos 1984).