taxonID	type	description	language	source
AE5564907A7C52A8B1C1F60DE0039565.taxon	description	Figs 6 A, B, 15	en	Qi, Zheng-Xiang, Wang, Li-Bo, Qian, Ke-Qing, Shi, Li-Li, Hu, Jia-Jun, Tuo, Yong-Lan, Rao, Gu, Samwel Jacob, Muharagi, Liu, Rui-Peng, Liu, Ming-Hao, Guo, Di-Zhe, Liu, Ya-Jie, Zhang, Bo, Li, Xiao, Li, Yu (2025): Integrating morphology, phylogeny, substrate, and distribution: clarifying the major phylogenetic framework of Pluteus sect. Hispidoderma (Agaricales, Pluteaceae) and describing 18 species. IMA Fungus 16: e 154329, DOI: 10.3897/imafungus.16.154329
AE5564907A7C52A8B1C1F60DE0039565.taxon	etymology	Etymology. Derived from Latin ‘ albus’ (white) and ‘ villus’ (downy), referring to the white downy hairs on the pileus surface.	en	Qi, Zheng-Xiang, Wang, Li-Bo, Qian, Ke-Qing, Shi, Li-Li, Hu, Jia-Jun, Tuo, Yong-Lan, Rao, Gu, Samwel Jacob, Muharagi, Liu, Rui-Peng, Liu, Ming-Hao, Guo, Di-Zhe, Liu, Ya-Jie, Zhang, Bo, Li, Xiao, Li, Yu (2025): Integrating morphology, phylogeny, substrate, and distribution: clarifying the major phylogenetic framework of Pluteus sect. Hispidoderma (Agaricales, Pluteaceae) and describing 18 species. IMA Fungus 16: e 154329, DOI: 10.3897/imafungus.16.154329
AE5564907A7C52A8B1C1F60DE0039565.taxon	diagnosis	Diagnosis. Pluteus albivillus differs from P. velutinus by its pileus surface with white villi, flocculose lamellae edges, fibrous stipe, and two forms of pleurocystidia (fusiform and narrowly clavate to clavate). The ITS genetic distance is 0.058 (SE = 0.010), tef 1 genetic distance is 0.106 (SE = 0.031).	en	Qi, Zheng-Xiang, Wang, Li-Bo, Qian, Ke-Qing, Shi, Li-Li, Hu, Jia-Jun, Tuo, Yong-Lan, Rao, Gu, Samwel Jacob, Muharagi, Liu, Rui-Peng, Liu, Ming-Hao, Guo, Di-Zhe, Liu, Ya-Jie, Zhang, Bo, Li, Xiao, Li, Yu (2025): Integrating morphology, phylogeny, substrate, and distribution: clarifying the major phylogenetic framework of Pluteus sect. Hispidoderma (Agaricales, Pluteaceae) and describing 18 species. IMA Fungus 16: e 154329, DOI: 10.3897/imafungus.16.154329
AE5564907A7C52A8B1C1F60DE0039565.taxon	description	Description. Basidiomata medium-sized. Pileus 24 – 29 mm diam; hemispherical when young, brown (10 R 5 / 2); expanding to convex, moderate reddish brown (10 R 5 / 2) to weak reddish brown (2.5 R 5 / 2); surface covered with fine villous covering when dry, hygrophanous when damp, smooth, margin inflexed. Lamellae free, 3 – 5 mm wide, crowded, initially white (10 P 9 / 2) to later pink (5 R 9 / 2), unequal, thicker, with flocculose edges; lamellar edge concolorous to the sides. Stipe 30 – 35 × 3 – 5 mm, clavate, slightly expanded at the base, fibrous, surface with longitudinal striate, hyaline to white (10 P 9 / 2) in the upper part, transitioning downward to brown (10 R 5 / 2) to dark brown (2.5 R 5 / 2). Spore print unknown. Basidiospores [90 / 3 / 1] (– 6.5) 7.0 – 8.0 (– 8.5) × 5.5 – 6.5 (– 7.0) µm, avL × avW = 7.3 – 7.6 × 5.8 – 6.0 µm, Q = 1.07 – 1.34 µm, avQ = 1.20 – 1.25 µm, subglobose, broadly ellipsoid to ellipsoid, smooth, slightly pinkish, thin-walled. Basidia 26 – 32 × 7 – 10 μm, clavate, thin-walled, 4 - sterigmate, hyaline. Pleurocystidia 49 – 86 × 20 – 36 μm, few, scattered, two forms, one narrowly clavate to clavate, bluntly rounded apically, the other long fusiform, pointed apically, thin-walled, smooth, hyaline. Lamellar edge sterile. Cheilocystidia 35 – 66 × 12 – 21 μm, abundant, clustered, clavate, pyriform to narrowly clavate, smooth, thin-walled, hyaline. Pileipellis a hymeniderm formed of variable and often mixed elements, from short and rounded to clavate, subfusiform or cylindrical terminal elements, 57 – 130 × 15 – 36 μm, with pale brown intracellular pigment, thin-walled. Stipitipellis a cutis, hyphae 3 – 6 μm diam, cylindrical, hyaline, thin-walled. Caulocystidia 33 – 67 × 11 – 20 μm, clustered, narrowly clavate to clavate, apically obtusely rounded, smooth, thin-walled, hyaline. Clamp connections absent in all tissues.	en	Qi, Zheng-Xiang, Wang, Li-Bo, Qian, Ke-Qing, Shi, Li-Li, Hu, Jia-Jun, Tuo, Yong-Lan, Rao, Gu, Samwel Jacob, Muharagi, Liu, Rui-Peng, Liu, Ming-Hao, Guo, Di-Zhe, Liu, Ya-Jie, Zhang, Bo, Li, Xiao, Li, Yu (2025): Integrating morphology, phylogeny, substrate, and distribution: clarifying the major phylogenetic framework of Pluteus sect. Hispidoderma (Agaricales, Pluteaceae) and describing 18 species. IMA Fungus 16: e 154329, DOI: 10.3897/imafungus.16.154329
AE5564907A7C52A8B1C1F60DE0039565.taxon	distribution	World distribution. China.	en	Qi, Zheng-Xiang, Wang, Li-Bo, Qian, Ke-Qing, Shi, Li-Li, Hu, Jia-Jun, Tuo, Yong-Lan, Rao, Gu, Samwel Jacob, Muharagi, Liu, Rui-Peng, Liu, Ming-Hao, Guo, Di-Zhe, Liu, Ya-Jie, Zhang, Bo, Li, Xiao, Li, Yu (2025): Integrating morphology, phylogeny, substrate, and distribution: clarifying the major phylogenetic framework of Pluteus sect. Hispidoderma (Agaricales, Pluteaceae) and describing 18 species. IMA Fungus 16: e 154329, DOI: 10.3897/imafungus.16.154329
AE5564907A7C52A8B1C1F60DE0039565.taxon	distribution	China distribution. Xinjiang Uygur Autonomous Region.	en	Qi, Zheng-Xiang, Wang, Li-Bo, Qian, Ke-Qing, Shi, Li-Li, Hu, Jia-Jun, Tuo, Yong-Lan, Rao, Gu, Samwel Jacob, Muharagi, Liu, Rui-Peng, Liu, Ming-Hao, Guo, Di-Zhe, Liu, Ya-Jie, Zhang, Bo, Li, Xiao, Li, Yu (2025): Integrating morphology, phylogeny, substrate, and distribution: clarifying the major phylogenetic framework of Pluteus sect. Hispidoderma (Agaricales, Pluteaceae) and describing 18 species. IMA Fungus 16: e 154329, DOI: 10.3897/imafungus.16.154329
7904921AC94657A28A8558B6A405800F.taxon	description	Figs 6 C – G, 14	en	Qi, Zheng-Xiang, Wang, Li-Bo, Qian, Ke-Qing, Shi, Li-Li, Hu, Jia-Jun, Tuo, Yong-Lan, Rao, Gu, Samwel Jacob, Muharagi, Liu, Rui-Peng, Liu, Ming-Hao, Guo, Di-Zhe, Liu, Ya-Jie, Zhang, Bo, Li, Xiao, Li, Yu (2025): Integrating morphology, phylogeny, substrate, and distribution: clarifying the major phylogenetic framework of Pluteus sect. Hispidoderma (Agaricales, Pluteaceae) and describing 18 species. IMA Fungus 16: e 154329, DOI: 10.3897/imafungus.16.154329
7904921AC94657A28A8558B6A405800F.taxon	etymology	Etymology. baishanzu, for the geographic origin of the type collection.	en	Qi, Zheng-Xiang, Wang, Li-Bo, Qian, Ke-Qing, Shi, Li-Li, Hu, Jia-Jun, Tuo, Yong-Lan, Rao, Gu, Samwel Jacob, Muharagi, Liu, Rui-Peng, Liu, Ming-Hao, Guo, Di-Zhe, Liu, Ya-Jie, Zhang, Bo, Li, Xiao, Li, Yu (2025): Integrating morphology, phylogeny, substrate, and distribution: clarifying the major phylogenetic framework of Pluteus sect. Hispidoderma (Agaricales, Pluteaceae) and describing 18 species. IMA Fungus 16: e 154329, DOI: 10.3897/imafungus.16.154329
7904921AC94657A28A8558B6A405800F.taxon	diagnosis	Diagnosis. Pluteus baishanzuensis differs from P. lauracearum by its brown glandular dots on the surface of the pileus, exceeding lamellae on the margin of the pileus, small basidiospores, and thin-walled pleurocystidia. The ITS genetic distance is 0.073 (SE = 0.014).	en	Qi, Zheng-Xiang, Wang, Li-Bo, Qian, Ke-Qing, Shi, Li-Li, Hu, Jia-Jun, Tuo, Yong-Lan, Rao, Gu, Samwel Jacob, Muharagi, Liu, Rui-Peng, Liu, Ming-Hao, Guo, Di-Zhe, Liu, Ya-Jie, Zhang, Bo, Li, Xiao, Li, Yu (2025): Integrating morphology, phylogeny, substrate, and distribution: clarifying the major phylogenetic framework of Pluteus sect. Hispidoderma (Agaricales, Pluteaceae) and describing 18 species. IMA Fungus 16: e 154329, DOI: 10.3897/imafungus.16.154329
7904921AC94657A28A8558B6A405800F.taxon	description	Description. Basidiomata medium-sized. Pileus 23 – 32 mm diam; convex or plano-convex; surface white (2.5 Y 9 / 2), central part covered with brown (5 YR 5 / 2) to light brown (2.5 Y 5 / 2) glandular dots or finely pruinose, forming dark brown (2.5 YR 5 / 2) vein-like striate, extend to the margin; smooth, hygrophanous; margin exceeding lamellae. Context white (2.5 P 9 / 2). Lamellae free, 3 – 7 mm wide, moderately crowded, initially white (10 P 9 / 2) to later flesh-pink (5 R 9 / 2), unequal, thicker, slightly ventricose, edges flocculose, and white or slightly pink. Stipe 36 – 46 × 1 – 3 mm, fibrous, hollow, clavate, base expanded into a bulbous, the upper part of the stipe hyaline (2.5 P 9 / 2) to white (10 P 9 / 2), transitioning downward to brown (5 YR 5 / 2) to dark brown (2.5 YR 5 / 2), the surface covered with white finely pruinose (10 P 9 / 2). Spore print pink. Basidiospores [120 / 5 / 2] 6.0 – 6.5 (– 7.0) × 5.0 – 6.0 (– 6.5) µm, avL × avW = 6.2 – 6.5 × 5.3 – 5.6 µm, Q = 1.08 – 1.20 µm, avQ = 1.13 – 1.18 µm, subglobose to broadly ellipsoid, smooth, slightly pinkish, thin-walled. Basidia 24 – 31 × 8 – 12 μm, clavate to broadly clavate, thin-walled, 4 - sterigmate. Pleurocystidia 47 – 95 × 16 – 31 μm, rare, scattered, fusiform or broadly subfusiform, bluntly rounded apically, thin-walled, smooth, hyaline. Lamellar edge sterile. Cheilocystidia 35 – 66 × 12 – 21 μm, abundant, clustered, mostly clavate to narrowly clavate, a few subfusiform, bluntly rounded apically, thin-walled, smooth, hyaline. Pileipellis a hymeniderm, with terminal elements 66 – 133 × 19 – 25 μm, long clavate, narrowly clavate, subcylindric or subfusiform, thin-walled, with brown intracellular pigment. Stipitipellis a cutis, hyphae 4 – 7 μm diam, cylindrical, hyaline, thin-walled. Caulocystidia 31 – 53 × 15 – 28 μm, clustered, narrowly clavate to clavate or broadly clavate, apically obtusely rounded, with brownish intracellular pigment, smooth, thick-walled. Clamp connections absent in all tissues.	en	Qi, Zheng-Xiang, Wang, Li-Bo, Qian, Ke-Qing, Shi, Li-Li, Hu, Jia-Jun, Tuo, Yong-Lan, Rao, Gu, Samwel Jacob, Muharagi, Liu, Rui-Peng, Liu, Ming-Hao, Guo, Di-Zhe, Liu, Ya-Jie, Zhang, Bo, Li, Xiao, Li, Yu (2025): Integrating morphology, phylogeny, substrate, and distribution: clarifying the major phylogenetic framework of Pluteus sect. Hispidoderma (Agaricales, Pluteaceae) and describing 18 species. IMA Fungus 16: e 154329, DOI: 10.3897/imafungus.16.154329
7904921AC94657A28A8558B6A405800F.taxon	distribution	World distribution. China.	en	Qi, Zheng-Xiang, Wang, Li-Bo, Qian, Ke-Qing, Shi, Li-Li, Hu, Jia-Jun, Tuo, Yong-Lan, Rao, Gu, Samwel Jacob, Muharagi, Liu, Rui-Peng, Liu, Ming-Hao, Guo, Di-Zhe, Liu, Ya-Jie, Zhang, Bo, Li, Xiao, Li, Yu (2025): Integrating morphology, phylogeny, substrate, and distribution: clarifying the major phylogenetic framework of Pluteus sect. Hispidoderma (Agaricales, Pluteaceae) and describing 18 species. IMA Fungus 16: e 154329, DOI: 10.3897/imafungus.16.154329
7904921AC94657A28A8558B6A405800F.taxon	distribution	China distribution. Zhejiang Province.	en	Qi, Zheng-Xiang, Wang, Li-Bo, Qian, Ke-Qing, Shi, Li-Li, Hu, Jia-Jun, Tuo, Yong-Lan, Rao, Gu, Samwel Jacob, Muharagi, Liu, Rui-Peng, Liu, Ming-Hao, Guo, Di-Zhe, Liu, Ya-Jie, Zhang, Bo, Li, Xiao, Li, Yu (2025): Integrating morphology, phylogeny, substrate, and distribution: clarifying the major phylogenetic framework of Pluteus sect. Hispidoderma (Agaricales, Pluteaceae) and describing 18 species. IMA Fungus 16: e 154329, DOI: 10.3897/imafungus.16.154329
4D37257476025EE0861B126C6A929FE6.taxon	description	Figs 18 A – C, 19	en	Qi, Zheng-Xiang, Wang, Li-Bo, Qian, Ke-Qing, Shi, Li-Li, Hu, Jia-Jun, Tuo, Yong-Lan, Rao, Gu, Samwel Jacob, Muharagi, Liu, Rui-Peng, Liu, Ming-Hao, Guo, Di-Zhe, Liu, Ya-Jie, Zhang, Bo, Li, Xiao, Li, Yu (2025): Integrating morphology, phylogeny, substrate, and distribution: clarifying the major phylogenetic framework of Pluteus sect. Hispidoderma (Agaricales, Pluteaceae) and describing 18 species. IMA Fungus 16: e 154329, DOI: 10.3897/imafungus.16.154329
4D37257476025EE0861B126C6A929FE6.taxon	etymology	Etymology. The species epithet “ costatus ” (Lat.) refers to the ribbed (costatus) pileus, characterized by prominent veins, with a distinctly pronounced middle vein.	en	Qi, Zheng-Xiang, Wang, Li-Bo, Qian, Ke-Qing, Shi, Li-Li, Hu, Jia-Jun, Tuo, Yong-Lan, Rao, Gu, Samwel Jacob, Muharagi, Liu, Rui-Peng, Liu, Ming-Hao, Guo, Di-Zhe, Liu, Ya-Jie, Zhang, Bo, Li, Xiao, Li, Yu (2025): Integrating morphology, phylogeny, substrate, and distribution: clarifying the major phylogenetic framework of Pluteus sect. Hispidoderma (Agaricales, Pluteaceae) and describing 18 species. IMA Fungus 16: e 154329, DOI: 10.3897/imafungus.16.154329
4D37257476025EE0861B126C6A929FE6.taxon	diagnosis	Diagnosis. Morphologically similar to P. ornatus, differing in its unstriped pileus margins, smaller basidiospores avL × avW = 6.2 – 6.5 × 5.2 – 5.5 µm, and their ITS genetic distance is 0.029 (SE = 0.007). It grows in coniferous forests with decaying wood branches and is distributed in East Asia (China). Phylogenetically close to P. umbrosus and P. granularis, differing in the lamellae with brown edges.	en	Qi, Zheng-Xiang, Wang, Li-Bo, Qian, Ke-Qing, Shi, Li-Li, Hu, Jia-Jun, Tuo, Yong-Lan, Rao, Gu, Samwel Jacob, Muharagi, Liu, Rui-Peng, Liu, Ming-Hao, Guo, Di-Zhe, Liu, Ya-Jie, Zhang, Bo, Li, Xiao, Li, Yu (2025): Integrating morphology, phylogeny, substrate, and distribution: clarifying the major phylogenetic framework of Pluteus sect. Hispidoderma (Agaricales, Pluteaceae) and describing 18 species. IMA Fungus 16: e 154329, DOI: 10.3897/imafungus.16.154329
4D37257476025EE0861B126C6A929FE6.taxon	description	Description. Basidiomata medium-sized. Pileus 32 – 35 mm diam; convex or plano-convex, often with a low, broad umbo; overall silvery gray (5.0 YR 6 / 2), with brown granulose-squamulose or micaceous on the surface, forming a black-brown vein-like stripe (5.0 YR 4 / 10), very dense in the center; veins extended to the margin, gradually less; margin striaght. Lamellae white to light pink (2.5 YR 9 / 2 – 2.5 R 9 / 6), free, crowded, thick, unequal, 3 – 5 mm wide, with white to light brown and flocculose edges. Stipe 61 – 66 × 5 – 8 mm, cylindrical, hollow, fibrous, brown (5.0 YR 6 / 8), slightly thicker at the base. Odorless. Spore prints pink. Basidiospores [80, 3, 2] 6.0 – 6.5 (– 7.0) × 5.0 – 5.5 (– 6.0) μm, avL × avW = 6.2 – 6.5 × 5.2 – 5.5 µm, Q = 1.16 – 1.40 μm, avQ = 1.20 – 1.26 μm, broadly ellipsoid to ellipsoid, slightly pinkish, smooth, thin-walled. Basidia 20 – 28 × 7 – 9 μm, clavate, thin-walled, 4 - sterigmate, and hyaline. Pleurocystidia 49 – 95 × 22 – 33 μm, abundant, scattered, fusiform to flask-shaped, apically obtusely rounded or partially with 1 – 2 digitiform excrescences at apex, thinly walled, smooth, hyaline. Lamellar edge sterile. Cheilocystidia 41 – 70 × 16 – 25 μm, numerous, fusiform to narrowly clavate, or clavate, apically with a mucronate or rostrate, thin-walled, mostly with brown intracellular pigment. Pileipellis a trichohymeniderm composed of narrowed fusiform and clavate elements, terminal elements expanded to a spindle to clavate 62 – 140 long, 27 – 36 μm wide, thin-walled, with brown intracellular pigment. Stipitipellis a cutis, hyphae 5 – 10 µm diam, cylindrical, hyaline, thin-walled. Caulocystidia 53 – 108 × 11 – 22 μm, numerous, usually in clusters, spindle, or cylindrical to narrowly lageniform, rounded at apex, with brown to pale brown intracellular pigment, slightly thick and smooth walls. Clamp connections absent in all tissues.	en	Qi, Zheng-Xiang, Wang, Li-Bo, Qian, Ke-Qing, Shi, Li-Li, Hu, Jia-Jun, Tuo, Yong-Lan, Rao, Gu, Samwel Jacob, Muharagi, Liu, Rui-Peng, Liu, Ming-Hao, Guo, Di-Zhe, Liu, Ya-Jie, Zhang, Bo, Li, Xiao, Li, Yu (2025): Integrating morphology, phylogeny, substrate, and distribution: clarifying the major phylogenetic framework of Pluteus sect. Hispidoderma (Agaricales, Pluteaceae) and describing 18 species. IMA Fungus 16: e 154329, DOI: 10.3897/imafungus.16.154329
4D37257476025EE0861B126C6A929FE6.taxon	distribution	World distribution. China.	en	Qi, Zheng-Xiang, Wang, Li-Bo, Qian, Ke-Qing, Shi, Li-Li, Hu, Jia-Jun, Tuo, Yong-Lan, Rao, Gu, Samwel Jacob, Muharagi, Liu, Rui-Peng, Liu, Ming-Hao, Guo, Di-Zhe, Liu, Ya-Jie, Zhang, Bo, Li, Xiao, Li, Yu (2025): Integrating morphology, phylogeny, substrate, and distribution: clarifying the major phylogenetic framework of Pluteus sect. Hispidoderma (Agaricales, Pluteaceae) and describing 18 species. IMA Fungus 16: e 154329, DOI: 10.3897/imafungus.16.154329
4D37257476025EE0861B126C6A929FE6.taxon	distribution	China distribution. Heilongjiang Province, Jilin Province.	en	Qi, Zheng-Xiang, Wang, Li-Bo, Qian, Ke-Qing, Shi, Li-Li, Hu, Jia-Jun, Tuo, Yong-Lan, Rao, Gu, Samwel Jacob, Muharagi, Liu, Rui-Peng, Liu, Ming-Hao, Guo, Di-Zhe, Liu, Ya-Jie, Zhang, Bo, Li, Xiao, Li, Yu (2025): Integrating morphology, phylogeny, substrate, and distribution: clarifying the major phylogenetic framework of Pluteus sect. Hispidoderma (Agaricales, Pluteaceae) and describing 18 species. IMA Fungus 16: e 154329, DOI: 10.3897/imafungus.16.154329
AB5DA5C2493954F19A5787FE1FC22032.taxon	description	Figs 18 I, J, 22	en	Qi, Zheng-Xiang, Wang, Li-Bo, Qian, Ke-Qing, Shi, Li-Li, Hu, Jia-Jun, Tuo, Yong-Lan, Rao, Gu, Samwel Jacob, Muharagi, Liu, Rui-Peng, Liu, Ming-Hao, Guo, Di-Zhe, Liu, Ya-Jie, Zhang, Bo, Li, Xiao, Li, Yu (2025): Integrating morphology, phylogeny, substrate, and distribution: clarifying the major phylogenetic framework of Pluteus sect. Hispidoderma (Agaricales, Pluteaceae) and describing 18 species. IMA Fungus 16: e 154329, DOI: 10.3897/imafungus.16.154329
AB5DA5C2493954F19A5787FE1FC22032.taxon	description	Description. Basidiomata medium to large-sized. Pileus 30 – 51 mm diam; plano-convex to convex, slightly obtuse raised in the middle; yellow (10 YR 6 / 6) to yellow-brown (10 YR 5 / 6), with brown (5 YR 3 / 6) warped scales attached to the surface, the middle scales densely forming a vein-like, gradually becoming sparser toward the margin, with triangular scales toward the margin. Context white (10 P 9 / 2) and odorless. Lamellae free, 4 – 6 mm wide, crowded, yellowish-brown (2.5 YR 4 / 6), unequal, thin, ventricose, white and even to flocculose edges. Stipe 32 – 95 × 3 – 8 mm, fibrous, clavate, hollow, slightly expanded at the base, white (10 P 9 / 2) overall, with denser brown (10 YR 3 / 6) cilia on the middle to lower portion. Spore print unknown. Basidiospores [60 / 2 / 1] 5.5 – 6.0 (– 6.5) × 4.5 – 5.0 µm, avL × avW = 5.7 – 6.0 × 4.6 – 4.8 µm, Q = 1.10 – 1.30 µm, avQ = 1.20 µm, subglobose, broadly ellipsoid to ellipsoid, smooth, slightly pinkish, thick-walled. Basidia 23 – 28 × 8 – 11 μm, broadly clavate, thin-walled, 4 - sterigmate, and hyaline. Pleurocystidia 55 – 83 × 15 – 33 μm, scattered, rare, two forms, one fusiform, with apical finger-like projections, 3 – 6 μm long, the other narrowly clavate to clavate, with an obtusely rounded apical portion, thin-walled, smooth, partly with brown intracellular pigment. Lamellar edge sterile. Cheilocystidia 34 – 65 × 13 – 22 μm, abundant, clustered, broadly clavate to clavate, apically obtuse, thin-walled, smooth, hyaline. Pileipellis a trichohymeniderm composed of narrowed fusiform and clavate elements, with terminal elements 130 – 216 × 17 – 31 μm, often aggregated into bundles, pointed towards the apex, with brown intracellular pigment, thin-walled, smooth. Stipitipellis a cutis, hyphae 4 – 6 μm diam, cylindrical, hyaline, thin-walled. Caulocystidia 36 – 55 × 13 – 19 μm, scattered, composed of long clavate to clavate vesicles, partly containing brownish pigment, thin-walled, smooth. Clamp connections absent in all tissues.	en	Qi, Zheng-Xiang, Wang, Li-Bo, Qian, Ke-Qing, Shi, Li-Li, Hu, Jia-Jun, Tuo, Yong-Lan, Rao, Gu, Samwel Jacob, Muharagi, Liu, Rui-Peng, Liu, Ming-Hao, Guo, Di-Zhe, Liu, Ya-Jie, Zhang, Bo, Li, Xiao, Li, Yu (2025): Integrating morphology, phylogeny, substrate, and distribution: clarifying the major phylogenetic framework of Pluteus sect. Hispidoderma (Agaricales, Pluteaceae) and describing 18 species. IMA Fungus 16: e 154329, DOI: 10.3897/imafungus.16.154329
AB5DA5C2493954F19A5787FE1FC22032.taxon	distribution	World distribution. USA (Peck 1885, 1899; Murrill 1917; Kauffman 1918; Bessette et al. 1997; Justo et al. 2011 b), Turkey (Kaygusuz et al. 2019), China (Yang 2011).	en	Qi, Zheng-Xiang, Wang, Li-Bo, Qian, Ke-Qing, Shi, Li-Li, Hu, Jia-Jun, Tuo, Yong-Lan, Rao, Gu, Samwel Jacob, Muharagi, Liu, Rui-Peng, Liu, Ming-Hao, Guo, Di-Zhe, Liu, Ya-Jie, Zhang, Bo, Li, Xiao, Li, Yu (2025): Integrating morphology, phylogeny, substrate, and distribution: clarifying the major phylogenetic framework of Pluteus sect. Hispidoderma (Agaricales, Pluteaceae) and describing 18 species. IMA Fungus 16: e 154329, DOI: 10.3897/imafungus.16.154329
AB5DA5C2493954F19A5787FE1FC22032.taxon	distribution	China distribution. Jilin Province, Sichuan Province, Yunnan Province, Tibet Autonomous Region (Yang 2011).	en	Qi, Zheng-Xiang, Wang, Li-Bo, Qian, Ke-Qing, Shi, Li-Li, Hu, Jia-Jun, Tuo, Yong-Lan, Rao, Gu, Samwel Jacob, Muharagi, Liu, Rui-Peng, Liu, Ming-Hao, Guo, Di-Zhe, Liu, Ya-Jie, Zhang, Bo, Li, Xiao, Li, Yu (2025): Integrating morphology, phylogeny, substrate, and distribution: clarifying the major phylogenetic framework of Pluteus sect. Hispidoderma (Agaricales, Pluteaceae) and describing 18 species. IMA Fungus 16: e 154329, DOI: 10.3897/imafungus.16.154329
FD3B3022FFBF513999B7E02A4B4293CA.taxon	description	Figs 7 D, E, 13	en	Qi, Zheng-Xiang, Wang, Li-Bo, Qian, Ke-Qing, Shi, Li-Li, Hu, Jia-Jun, Tuo, Yong-Lan, Rao, Gu, Samwel Jacob, Muharagi, Liu, Rui-Peng, Liu, Ming-Hao, Guo, Di-Zhe, Liu, Ya-Jie, Zhang, Bo, Li, Xiao, Li, Yu (2025): Integrating morphology, phylogeny, substrate, and distribution: clarifying the major phylogenetic framework of Pluteus sect. Hispidoderma (Agaricales, Pluteaceae) and describing 18 species. IMA Fungus 16: e 154329, DOI: 10.3897/imafungus.16.154329
FD3B3022FFBF513999B7E02A4B4293CA.taxon	etymology	Etymology. The species epithet “ hinnuleus ” (Latin): refers to the clay-buff to earthy yellow pileus color.	en	Qi, Zheng-Xiang, Wang, Li-Bo, Qian, Ke-Qing, Shi, Li-Li, Hu, Jia-Jun, Tuo, Yong-Lan, Rao, Gu, Samwel Jacob, Muharagi, Liu, Rui-Peng, Liu, Ming-Hao, Guo, Di-Zhe, Liu, Ya-Jie, Zhang, Bo, Li, Xiao, Li, Yu (2025): Integrating morphology, phylogeny, substrate, and distribution: clarifying the major phylogenetic framework of Pluteus sect. Hispidoderma (Agaricales, Pluteaceae) and describing 18 species. IMA Fungus 16: e 154329, DOI: 10.3897/imafungus.16.154329
FD3B3022FFBF513999B7E02A4B4293CA.taxon	diagnosis	Diagnosis. Pluteus hinnuleus differs from P. albivillus by its clay-buff to earthy yellow pileus color, small basidiospores, pleurocystidia with 1 – 7 μm finger-like projections on the apex. It grows preferentially in birch forests (Betula) on decaying wood branches and is distributed in Northeast China. The ITS genetic distance is 0.125 (SE = 0.017).	en	Qi, Zheng-Xiang, Wang, Li-Bo, Qian, Ke-Qing, Shi, Li-Li, Hu, Jia-Jun, Tuo, Yong-Lan, Rao, Gu, Samwel Jacob, Muharagi, Liu, Rui-Peng, Liu, Ming-Hao, Guo, Di-Zhe, Liu, Ya-Jie, Zhang, Bo, Li, Xiao, Li, Yu (2025): Integrating morphology, phylogeny, substrate, and distribution: clarifying the major phylogenetic framework of Pluteus sect. Hispidoderma (Agaricales, Pluteaceae) and describing 18 species. IMA Fungus 16: e 154329, DOI: 10.3897/imafungus.16.154329
FD3B3022FFBF513999B7E02A4B4293CA.taxon	description	Description. Basidiomata medium-sized. Pileus 34 mm diam; convex to slightly hemispherical; clay-buff to earthy yellow (2.5 Y 8 / 6), dry, the surface with recurved squamules, the central scales color dark brown (10 YR 4 / 6), the margin slightly inflexed. Lamellae free, 3 – 5 mm wide, moderately crowded, thick, pink (2.5 YR 7 / 4), unequal, slightly ventricose, edges even or flocculose; lamellar edge concolorous to the sides. Stipe 43 × 4 – 7 mm, fibrous, solid, earthy yellow (2.5 Y 8 / 6), with brown glandular dots on the surface (7.5 YR 4 / 2), slightly inflated at the base. Spore print pink. Basidiospores [50 / 1 / 1] 6.5 – 7.5 (– 8.0) × (– 5.0) 5.5 – 6.5 (– 7.0) µm, avL × avW = 6.8 – 7.2 × 5.7 – 6.0 µm, Q = 1.16 – 1.33 µm, avQ = 1.20 – 1.25 µm, mostly subglobose, broadly ellipsoid to ellipsoid, smooth, slightly pinkish, thin-walled. Basidia 25 – 34 × 9 – 11 μm, clavate, thin-walled, 4 - sterigmate, hyaline. Pleurocystidia 60 – 93 × 20 – 35 μm, abundant, scattered, two forms, one broadly fusiform with bluntly rounded apices, the other narrowly fusiform with a longer neck and unequal apical rostrate, long projection 3 – 7 μm long, thin-walled, smooth, hyaline. Lamellar edge sterile. Cheilocystidia 43 – 78 × 15 – 24 μm, clustered, numerous, broadly clavate to clavate, apically obtuse, partly with brown intracellular pigment, thin-walled, smooth. Pileipellis a hymeniderm, with terminal elements 81 – 155 × 19 – 33 μm, broadly clavate or broadly cylindrical, thin-walled, with brown intracellular pigment. Stipitipellis a cutis, hyphae 4 – 6 μm diam, cylindrical, hyaline, thin-walled. Caulocystidia 31 – 51 × 15 – 25 μm, clustered, long clavate, apically obtusely rounded, with brownish intracellular pigment, smooth, thick-walled. Clamp connections absent in all tissues.	en	Qi, Zheng-Xiang, Wang, Li-Bo, Qian, Ke-Qing, Shi, Li-Li, Hu, Jia-Jun, Tuo, Yong-Lan, Rao, Gu, Samwel Jacob, Muharagi, Liu, Rui-Peng, Liu, Ming-Hao, Guo, Di-Zhe, Liu, Ya-Jie, Zhang, Bo, Li, Xiao, Li, Yu (2025): Integrating morphology, phylogeny, substrate, and distribution: clarifying the major phylogenetic framework of Pluteus sect. Hispidoderma (Agaricales, Pluteaceae) and describing 18 species. IMA Fungus 16: e 154329, DOI: 10.3897/imafungus.16.154329
FD3B3022FFBF513999B7E02A4B4293CA.taxon	distribution	World distribution. China.	en	Qi, Zheng-Xiang, Wang, Li-Bo, Qian, Ke-Qing, Shi, Li-Li, Hu, Jia-Jun, Tuo, Yong-Lan, Rao, Gu, Samwel Jacob, Muharagi, Liu, Rui-Peng, Liu, Ming-Hao, Guo, Di-Zhe, Liu, Ya-Jie, Zhang, Bo, Li, Xiao, Li, Yu (2025): Integrating morphology, phylogeny, substrate, and distribution: clarifying the major phylogenetic framework of Pluteus sect. Hispidoderma (Agaricales, Pluteaceae) and describing 18 species. IMA Fungus 16: e 154329, DOI: 10.3897/imafungus.16.154329
FD3B3022FFBF513999B7E02A4B4293CA.taxon	distribution	China distribution. Heilongjiang Province.	en	Qi, Zheng-Xiang, Wang, Li-Bo, Qian, Ke-Qing, Shi, Li-Li, Hu, Jia-Jun, Tuo, Yong-Lan, Rao, Gu, Samwel Jacob, Muharagi, Liu, Rui-Peng, Liu, Ming-Hao, Guo, Di-Zhe, Liu, Ya-Jie, Zhang, Bo, Li, Xiao, Li, Yu (2025): Integrating morphology, phylogeny, substrate, and distribution: clarifying the major phylogenetic framework of Pluteus sect. Hispidoderma (Agaricales, Pluteaceae) and describing 18 species. IMA Fungus 16: e 154329, DOI: 10.3897/imafungus.16.154329
DDE8ACF82F015C818DA25E92F33098C6.taxon	description	Figs 5 E – G, 10	en	Qi, Zheng-Xiang, Wang, Li-Bo, Qian, Ke-Qing, Shi, Li-Li, Hu, Jia-Jun, Tuo, Yong-Lan, Rao, Gu, Samwel Jacob, Muharagi, Liu, Rui-Peng, Liu, Ming-Hao, Guo, Di-Zhe, Liu, Ya-Jie, Zhang, Bo, Li, Xiao, Li, Yu (2025): Integrating morphology, phylogeny, substrate, and distribution: clarifying the major phylogenetic framework of Pluteus sect. Hispidoderma (Agaricales, Pluteaceae) and describing 18 species. IMA Fungus 16: e 154329, DOI: 10.3897/imafungus.16.154329
DDE8ACF82F015C818DA25E92F33098C6.taxon	etymology	Etymology. jilin, for the geographic origin of the type collection.	en	Qi, Zheng-Xiang, Wang, Li-Bo, Qian, Ke-Qing, Shi, Li-Li, Hu, Jia-Jun, Tuo, Yong-Lan, Rao, Gu, Samwel Jacob, Muharagi, Liu, Rui-Peng, Liu, Ming-Hao, Guo, Di-Zhe, Liu, Ya-Jie, Zhang, Bo, Li, Xiao, Li, Yu (2025): Integrating morphology, phylogeny, substrate, and distribution: clarifying the major phylogenetic framework of Pluteus sect. Hispidoderma (Agaricales, Pluteaceae) and describing 18 species. IMA Fungus 16: e 154329, DOI: 10.3897/imafungus.16.154329
DDE8ACF82F015C818DA25E92F33098C6.taxon	diagnosis	Diagnosis. Pluteus jilinensis is separated from P. spaniophyllus by its burnt yellow pileus, with distinct squamules around the center, dense lamellae, and their ITS genetic distance is 0.008 (SE = 0.004), tef 1 genetic distance is 0.008 (SE = 0.004).	en	Qi, Zheng-Xiang, Wang, Li-Bo, Qian, Ke-Qing, Shi, Li-Li, Hu, Jia-Jun, Tuo, Yong-Lan, Rao, Gu, Samwel Jacob, Muharagi, Liu, Rui-Peng, Liu, Ming-Hao, Guo, Di-Zhe, Liu, Ya-Jie, Zhang, Bo, Li, Xiao, Li, Yu (2025): Integrating morphology, phylogeny, substrate, and distribution: clarifying the major phylogenetic framework of Pluteus sect. Hispidoderma (Agaricales, Pluteaceae) and describing 18 species. IMA Fungus 16: e 154329, DOI: 10.3897/imafungus.16.154329
DDE8ACF82F015C818DA25E92F33098C6.taxon	description	Description. Basidiomata small-sized. Pileus 15 – 21 mm diam; convex or plano-convex, often with a low, broad umbo; burnt yellow (5 YR 8 / 6) to gray-brown (10 YR 8 / 2), transitioning to light brown (2.5 Y 8 / 2) toward the margin; surface rough, with distinct squamules or rugose-venose around the center; margin crenulate, with small rounded or blunt teeth. Context yellowish (2.5 Y 9 / 2). Lamellae free, 3 – 5 mm wide, crowded, initially white (2.5 YR 9 / 2), pink at maturity (2.5 R 9 / 6), unequal, moderately thick, ventricose, edges even; lamellar edge concolorous to the sides. Stipe 21 – 45 × 2 – 4 mm, hollow, fibrous, clavate, slightly expanded at the base, transparent to whitish (7.5 RP 9 / 2) when young, light brown (5 YR 5 / 2) to brown (7.5 YR 5 / 4) at maturity. Spore print unknown. Basidiospores [60 / 5 / 2] 7.0 – 8.0 (– 8.5) × 6.0 – 7.0 (– 7.5) µm, avL × avW = 7.5 – 7.8 × 6.4 – 6.8 µm, Q = 1.07 – 1.25 µm, avQ = 1.15 – 1.20 µm, subglobose to broadly ellipsoid, smooth, slightly pinkish, thin-walled. Basidia 20 – 25 × 12 – 18 µm, broadly clavate, thin-walled, 4 - sterigmate, and hyaline. Pleurocystidia 55 – 83 × 15 – 23 μm, rare, scattered, fusiform to broadly fusiform, apically obtuse, thin-walled, smooth, partly containing brown intracellular pigment. Lamellar edge sterile. Cheilocystidia 37 – 63 × 16 – 21 μm, abundant, clustered, clavate, subfusiform to broadly fusiform, apically obtuse, with or without mucronate, thin-walled, smooth, hyaline. Pileipellis a hymeniderm, with terminal elements 75 – 98 × 17 – 28 μm, subcylindric or subfusiform, some apices with finger-like projections, thin-walled, with brown intracellular pigment. Stipitipellis a cutis, hyphae 5 – 8 μm diam, cylindrical, hyaline, thin-walled. Caulocystidia 36 – 55 × 13 – 19 μm, clustered, more numerous, composed of vesicles, subfusiform, bluntly rounded apically, partly containing brownish intracellular pigment, smooth, thin-walled. Clamp connections absent in all tissues.	en	Qi, Zheng-Xiang, Wang, Li-Bo, Qian, Ke-Qing, Shi, Li-Li, Hu, Jia-Jun, Tuo, Yong-Lan, Rao, Gu, Samwel Jacob, Muharagi, Liu, Rui-Peng, Liu, Ming-Hao, Guo, Di-Zhe, Liu, Ya-Jie, Zhang, Bo, Li, Xiao, Li, Yu (2025): Integrating morphology, phylogeny, substrate, and distribution: clarifying the major phylogenetic framework of Pluteus sect. Hispidoderma (Agaricales, Pluteaceae) and describing 18 species. IMA Fungus 16: e 154329, DOI: 10.3897/imafungus.16.154329
DDE8ACF82F015C818DA25E92F33098C6.taxon	distribution	World distribution. China.	en	Qi, Zheng-Xiang, Wang, Li-Bo, Qian, Ke-Qing, Shi, Li-Li, Hu, Jia-Jun, Tuo, Yong-Lan, Rao, Gu, Samwel Jacob, Muharagi, Liu, Rui-Peng, Liu, Ming-Hao, Guo, Di-Zhe, Liu, Ya-Jie, Zhang, Bo, Li, Xiao, Li, Yu (2025): Integrating morphology, phylogeny, substrate, and distribution: clarifying the major phylogenetic framework of Pluteus sect. Hispidoderma (Agaricales, Pluteaceae) and describing 18 species. IMA Fungus 16: e 154329, DOI: 10.3897/imafungus.16.154329
DDE8ACF82F015C818DA25E92F33098C6.taxon	distribution	China distribution. Jilin Province.	en	Qi, Zheng-Xiang, Wang, Li-Bo, Qian, Ke-Qing, Shi, Li-Li, Hu, Jia-Jun, Tuo, Yong-Lan, Rao, Gu, Samwel Jacob, Muharagi, Liu, Rui-Peng, Liu, Ming-Hao, Guo, Di-Zhe, Liu, Ya-Jie, Zhang, Bo, Li, Xiao, Li, Yu (2025): Integrating morphology, phylogeny, substrate, and distribution: clarifying the major phylogenetic framework of Pluteus sect. Hispidoderma (Agaricales, Pluteaceae) and describing 18 species. IMA Fungus 16: e 154329, DOI: 10.3897/imafungus.16.154329
75A12E12838A5BDFBB69E35B894B16B3.taxon	description	Figs 25 F – H, 29	en	Qi, Zheng-Xiang, Wang, Li-Bo, Qian, Ke-Qing, Shi, Li-Li, Hu, Jia-Jun, Tuo, Yong-Lan, Rao, Gu, Samwel Jacob, Muharagi, Liu, Rui-Peng, Liu, Ming-Hao, Guo, Di-Zhe, Liu, Ya-Jie, Zhang, Bo, Li, Xiao, Li, Yu (2025): Integrating morphology, phylogeny, substrate, and distribution: clarifying the major phylogenetic framework of Pluteus sect. Hispidoderma (Agaricales, Pluteaceae) and describing 18 species. IMA Fungus 16: e 154329, DOI: 10.3897/imafungus.16.154329
75A12E12838A5BDFBB69E35B894B16B3.taxon	description	Description. Basidiomata medium-sized. Pileus 20 – 31 mm diam; convex to plano-convex, often with a low, broad umbo; egg-yellow (5.0 Y 9 / 12), black-brown in the center (2.5 YR 5 / 8), with white pruinose on the surface, margin usually translucently striate. Lamellae flesh pink (2.5 YR 8 / 6), free, slightly crowded, thick, unequal, slightly ventricose, 3 – 5 mm wide. Stipe 37 – 48 × 4 – 7 mm, cylindrical, hollow, partly spirally twisted, base slightly thick, fibrous, surface smooth. Odorless. Spore prints pink. Basidiospores [150, 5, 3] 6.0 – 7.0 (– 7.5) × 5.0 – 6.0 (– 6.5) μm, avL × avW = 6.5 – 7.0 × 5.5 – 5.8 µm, Q = 1.15 – 1.40 μm, avQ = 1.18 – 1.26 μm, subglobose to broadly ellipsoid, ellipsoid or ovoid, slightly pinkish, smooth, thin-walled. Basidia 24 – 29 × 7 – 10 μm, clavate, thin-walled, 4 - sterigmate, hyaline. Pleurocystidia 50 – 86 × 20 – 26 μm, numerous, scattered, fusiform to utriform, apically obtusely rounded, commonly provided with 1 – 4 digitiform excrescences at apex, slightly thick-walled, smooth, hyaline. Lamellar edge sterile. Cheilocystidia 35 – 72 × 13 – 25 μm, similar in form to pleurocystidia, numerous, narrowly fusiform to utriform, with 1 – 2 digitate or mucronate apically, thin-walled, hyaline. Pileipellis a trichoderm with radial hyphae, with terminal elements 43 – 157 × 13 – 31 μm, hyphae at the center extending outwards, with cylindrical or fusiform elements, thick-walled, with slightly yellowish intracellular pigment. Stipitipellis a cutis, hyphae 4 – 11 µm diam, cylindrical, hyaline, non-incrusted, non-gelatinous, and thin-walled. Caulocystidia absent. Clamp connections absent in all tissues.	en	Qi, Zheng-Xiang, Wang, Li-Bo, Qian, Ke-Qing, Shi, Li-Li, Hu, Jia-Jun, Tuo, Yong-Lan, Rao, Gu, Samwel Jacob, Muharagi, Liu, Rui-Peng, Liu, Ming-Hao, Guo, Di-Zhe, Liu, Ya-Jie, Zhang, Bo, Li, Xiao, Li, Yu (2025): Integrating morphology, phylogeny, substrate, and distribution: clarifying the major phylogenetic framework of Pluteus sect. Hispidoderma (Agaricales, Pluteaceae) and describing 18 species. IMA Fungus 16: e 154329, DOI: 10.3897/imafungus.16.154329
75A12E12838A5BDFBB69E35B894B16B3.taxon	distribution	World distribution. Europe (Rea 1922; Vellinga and Schreurs 1985; Orton 1986; Vellinga 1990; Breitenbach and Kränzlin 1995; Krieglsteiner 2003; Boccardo et al. 2008; Heilmann-Clausen 2008), Asia (Takehashi and Kasuya 2007), North America (Murrill 1917; Kauffman 1918; Singer 1956) and North Africa (Malençon and Bertault 1970).	en	Qi, Zheng-Xiang, Wang, Li-Bo, Qian, Ke-Qing, Shi, Li-Li, Hu, Jia-Jun, Tuo, Yong-Lan, Rao, Gu, Samwel Jacob, Muharagi, Liu, Rui-Peng, Liu, Ming-Hao, Guo, Di-Zhe, Liu, Ya-Jie, Zhang, Bo, Li, Xiao, Li, Yu (2025): Integrating morphology, phylogeny, substrate, and distribution: clarifying the major phylogenetic framework of Pluteus sect. Hispidoderma (Agaricales, Pluteaceae) and describing 18 species. IMA Fungus 16: e 154329, DOI: 10.3897/imafungus.16.154329
75A12E12838A5BDFBB69E35B894B16B3.taxon	distribution	China distribution. It is distributed in all provinces of China (Xu 2016).	en	Qi, Zheng-Xiang, Wang, Li-Bo, Qian, Ke-Qing, Shi, Li-Li, Hu, Jia-Jun, Tuo, Yong-Lan, Rao, Gu, Samwel Jacob, Muharagi, Liu, Rui-Peng, Liu, Ming-Hao, Guo, Di-Zhe, Liu, Ya-Jie, Zhang, Bo, Li, Xiao, Li, Yu (2025): Integrating morphology, phylogeny, substrate, and distribution: clarifying the major phylogenetic framework of Pluteus sect. Hispidoderma (Agaricales, Pluteaceae) and describing 18 species. IMA Fungus 16: e 154329, DOI: 10.3897/imafungus.16.154329
A75D4DD24403538C86B0E16639CA1164.taxon	description	Figs 6 K, L, 17	en	Qi, Zheng-Xiang, Wang, Li-Bo, Qian, Ke-Qing, Shi, Li-Li, Hu, Jia-Jun, Tuo, Yong-Lan, Rao, Gu, Samwel Jacob, Muharagi, Liu, Rui-Peng, Liu, Ming-Hao, Guo, Di-Zhe, Liu, Ya-Jie, Zhang, Bo, Li, Xiao, Li, Yu (2025): Integrating morphology, phylogeny, substrate, and distribution: clarifying the major phylogenetic framework of Pluteus sect. Hispidoderma (Agaricales, Pluteaceae) and describing 18 species. IMA Fungus 16: e 154329, DOI: 10.3897/imafungus.16.154329
A75D4DD24403538C86B0E16639CA1164.taxon	description	Description. Basidiomata medium-sized. Pileus 31 – 35 mm diam; hemispherical to plano-convex, smooth, surface brownish-brown (5.0 YR 6 / 10), darker in the center (5.0 YR 4 / 10), with brown longitudinal striate extending from the middle to the margin. Lamellae dirty white (5.0 YR 9 / 4), free, relatively crowded, thick, unequal, slightly ventricose, 2 – 4 mm wide, with even edges. Stipe 26 – 31 × 3 – 5 mm, cylindrical, slightly thicker at the base, fibrous, with white longitudinal fibrils on the surface (5.0 YR 9 / 2). Odorless. Spore prints pink. Basidiospores [60, 3, 1] (– 6.0) 6.5 – 7.0 (– 7.5) × 5.0 – 6.0 (– 6.5) μm, avL × avW = 6.7 – 7.0 × 5.8 – 6.1 µm, Q = 1.03 – 1.25 μm, avQ = 1.06 – 1.15 μm, globose to subglobose, or broadly ellipsoid, slightly pinkish, smooth, thin-walled or slightly thick. Basidia 25 – 31 × 9 – 11 μm, broadly rod-shaped or clavate, thin-walled, 4 - sterigmate, hyaline. Pleurocystidia 55 – 88 × 16 – 27 μm, numerous, scattered, fusiform or narrowly utriform, apically obtusely rounded, thin-walled, smooth, hyaline. Lamellar edge sterile. Cheilocystidia 41 – 76 × 18 – 25 μm, abundant, clustered, narrowly clavate to clavate or long clavate, thin-walled, hyaline. Pileipellis a hymeniderm, with terminal elements 60 – 114 × 19 – 28 μm, broadly clavate or fusiform, thin-walled, with brown intracellular pigment. Stipitipellis a cutis, hyphae 4 – 11 µm diam, cylindrical, hyaline, thin-walled. Caulocystidia 29 – 72 × 12 – 26 μm, numerous, occurring in clusters, clavate to oblong-clavate, or fusiform, apically obtuse or mucronate, hyaline, thin-walled. Clamp connections absent in all tissues.	en	Qi, Zheng-Xiang, Wang, Li-Bo, Qian, Ke-Qing, Shi, Li-Li, Hu, Jia-Jun, Tuo, Yong-Lan, Rao, Gu, Samwel Jacob, Muharagi, Liu, Rui-Peng, Liu, Ming-Hao, Guo, Di-Zhe, Liu, Ya-Jie, Zhang, Bo, Li, Xiao, Li, Yu (2025): Integrating morphology, phylogeny, substrate, and distribution: clarifying the major phylogenetic framework of Pluteus sect. Hispidoderma (Agaricales, Pluteaceae) and describing 18 species. IMA Fungus 16: e 154329, DOI: 10.3897/imafungus.16.154329
A75D4DD24403538C86B0E16639CA1164.taxon	distribution	World distribution. USA, Paraguay, Brazil, Argentina (Justo et al. 2011 a; Ferisin and Dovana 2016; Campi et al. 2019), China (Xu 2016).	en	Qi, Zheng-Xiang, Wang, Li-Bo, Qian, Ke-Qing, Shi, Li-Li, Hu, Jia-Jun, Tuo, Yong-Lan, Rao, Gu, Samwel Jacob, Muharagi, Liu, Rui-Peng, Liu, Ming-Hao, Guo, Di-Zhe, Liu, Ya-Jie, Zhang, Bo, Li, Xiao, Li, Yu (2025): Integrating morphology, phylogeny, substrate, and distribution: clarifying the major phylogenetic framework of Pluteus sect. Hispidoderma (Agaricales, Pluteaceae) and describing 18 species. IMA Fungus 16: e 154329, DOI: 10.3897/imafungus.16.154329
A75D4DD24403538C86B0E16639CA1164.taxon	distribution	China distribution. Yunnan Province, Jilin Province (Xu 2016).	en	Qi, Zheng-Xiang, Wang, Li-Bo, Qian, Ke-Qing, Shi, Li-Li, Hu, Jia-Jun, Tuo, Yong-Lan, Rao, Gu, Samwel Jacob, Muharagi, Liu, Rui-Peng, Liu, Ming-Hao, Guo, Di-Zhe, Liu, Ya-Jie, Zhang, Bo, Li, Xiao, Li, Yu (2025): Integrating morphology, phylogeny, substrate, and distribution: clarifying the major phylogenetic framework of Pluteus sect. Hispidoderma (Agaricales, Pluteaceae) and describing 18 species. IMA Fungus 16: e 154329, DOI: 10.3897/imafungus.16.154329
7D4C12CF839A5D779D0C02CF8DB52A36.taxon	description	Figs 23 A – K, 24 A – M, 27	en	Qi, Zheng-Xiang, Wang, Li-Bo, Qian, Ke-Qing, Shi, Li-Li, Hu, Jia-Jun, Tuo, Yong-Lan, Rao, Gu, Samwel Jacob, Muharagi, Liu, Rui-Peng, Liu, Ming-Hao, Guo, Di-Zhe, Liu, Ya-Jie, Zhang, Bo, Li, Xiao, Li, Yu (2025): Integrating morphology, phylogeny, substrate, and distribution: clarifying the major phylogenetic framework of Pluteus sect. Hispidoderma (Agaricales, Pluteaceae) and describing 18 species. IMA Fungus 16: e 154329, DOI: 10.3897/imafungus.16.154329
7D4C12CF839A5D779D0C02CF8DB52A36.taxon	etymology	Etymology. The species epithet “ piceicola ” (Latin) refers to its habitat on Picea schrenkiana.	en	Qi, Zheng-Xiang, Wang, Li-Bo, Qian, Ke-Qing, Shi, Li-Li, Hu, Jia-Jun, Tuo, Yong-Lan, Rao, Gu, Samwel Jacob, Muharagi, Liu, Rui-Peng, Liu, Ming-Hao, Guo, Di-Zhe, Liu, Ya-Jie, Zhang, Bo, Li, Xiao, Li, Yu (2025): Integrating morphology, phylogeny, substrate, and distribution: clarifying the major phylogenetic framework of Pluteus sect. Hispidoderma (Agaricales, Pluteaceae) and describing 18 species. IMA Fungus 16: e 154329, DOI: 10.3897/imafungus.16.154329
7D4C12CF839A5D779D0C02CF8DB52A36.taxon	diagnosis	Diagnosis. Distinguished from P. leoninus by its pileus with a brown pruinose on the surface and the presence of spiral longitudinal striate of the stipe. On the phylogenetic tree, there are separate branches and its ITS sequences (genetic distance = 0.021, SE = 0.006) and tef 1 sequences (genetic distance = 0.090, SE = 0.015). It grows preferentially in coniferous forests (Picea) on decaying wood branches and is distributed in East Asia (China).	en	Qi, Zheng-Xiang, Wang, Li-Bo, Qian, Ke-Qing, Shi, Li-Li, Hu, Jia-Jun, Tuo, Yong-Lan, Rao, Gu, Samwel Jacob, Muharagi, Liu, Rui-Peng, Liu, Ming-Hao, Guo, Di-Zhe, Liu, Ya-Jie, Zhang, Bo, Li, Xiao, Li, Yu (2025): Integrating morphology, phylogeny, substrate, and distribution: clarifying the major phylogenetic framework of Pluteus sect. Hispidoderma (Agaricales, Pluteaceae) and describing 18 species. IMA Fungus 16: e 154329, DOI: 10.3897/imafungus.16.154329
7D4C12CF839A5D779D0C02CF8DB52A36.taxon	description	Description. Basidiomata medium to large-sized. Pileus 39 – 71 mm diam; campanulate to hemispherical when young, surface yellow-brown (10.0 YR 8 / 20), with yellow-brown crumbly scales, central scales crowded; gradually plano-convex to convex at maturity, central obtuse umbo, earthy yellow to orange-yellow (10.0 YR 8 / 10 – 10.0 YR 7 / 14), surface brown pruinose, margin yellow (10.0 YR 8 / 10). Context dirt white to yellowish (10.0 YR 8 / 2 – 10.0 YR 8 / 4), odorless, 5 – 8 mm thick. Lamellae initially dirty white (10.0 YR 8 / 4), turning pink at maturity (2.5 Y 8 / 12), free, crowded, thick, unequal, slightly ventricose, 6 – 7 mm wide, edges even. Stipe 47 – 71 × 8 – 13 mm, cylindrical, hollow, slightly thicker at the base, fibrous, some surfaces with brown longitudinal striate (7.5 YR 7 / 14). Odorless. Spore prints pink. Basidiospores [200, 30, 17] (– 6.5) 7.0 – 8.0 (– 8.5) × 5.5 – 6.0 (– 6.5) μm, avL × avW = 7.4 – 7.6 × 5.6 – 6.0 µm, Q = 1.16 – 1.54 μm, avQ = 1.20 – 1.25 μm, ellipsoid to broadly ellipsoid, slightly pinkish, smooth, thin-walled. Basidia 25 – 32 × 7 – 11 μm, clavate, thin-walled, 4 - sterigmate, and hyaline. Pleurocystidia 55 – 102 × 22 – 36 μm, numerous, scattered, fusiform to subfusiform, or clavate, apically mostly obtusely rounded, with or without 1 – 2 digitiform excrescences at apex, thin-walled, smooth, hyaline. Lamellar edge sterile. Cheilocystidia 41 – 79 × 18 – 29 μm, abundant, clustered, subfusiform to fusiform, mostly apically mucronate to rostrate, or diverticulate, 10 – 23 μm long, a few obtusely rounded, thin-walled, hyaline. Pileipellis a trichoderm with radial hyphae, terminal elements 62 – 171 × 17 – 32 μm, cylindrical or fusiform elements, thick-walled, and slightly tan intracellular pigment. Stipitipellis a cutis, hyphae 5 – 13 µm diam, cylindrical, hyaline, thin-walled. Caulocystidia absent. Clamp connections absent in all tissues.	en	Qi, Zheng-Xiang, Wang, Li-Bo, Qian, Ke-Qing, Shi, Li-Li, Hu, Jia-Jun, Tuo, Yong-Lan, Rao, Gu, Samwel Jacob, Muharagi, Liu, Rui-Peng, Liu, Ming-Hao, Guo, Di-Zhe, Liu, Ya-Jie, Zhang, Bo, Li, Xiao, Li, Yu (2025): Integrating morphology, phylogeny, substrate, and distribution: clarifying the major phylogenetic framework of Pluteus sect. Hispidoderma (Agaricales, Pluteaceae) and describing 18 species. IMA Fungus 16: e 154329, DOI: 10.3897/imafungus.16.154329
7D4C12CF839A5D779D0C02CF8DB52A36.taxon	distribution	World distribution. China.	en	Qi, Zheng-Xiang, Wang, Li-Bo, Qian, Ke-Qing, Shi, Li-Li, Hu, Jia-Jun, Tuo, Yong-Lan, Rao, Gu, Samwel Jacob, Muharagi, Liu, Rui-Peng, Liu, Ming-Hao, Guo, Di-Zhe, Liu, Ya-Jie, Zhang, Bo, Li, Xiao, Li, Yu (2025): Integrating morphology, phylogeny, substrate, and distribution: clarifying the major phylogenetic framework of Pluteus sect. Hispidoderma (Agaricales, Pluteaceae) and describing 18 species. IMA Fungus 16: e 154329, DOI: 10.3897/imafungus.16.154329
7D4C12CF839A5D779D0C02CF8DB52A36.taxon	distribution	China distribution. Xinjiang Uygur Autonomous Region.	en	Qi, Zheng-Xiang, Wang, Li-Bo, Qian, Ke-Qing, Shi, Li-Li, Hu, Jia-Jun, Tuo, Yong-Lan, Rao, Gu, Samwel Jacob, Muharagi, Liu, Rui-Peng, Liu, Ming-Hao, Guo, Di-Zhe, Liu, Ya-Jie, Zhang, Bo, Li, Xiao, Li, Yu (2025): Integrating morphology, phylogeny, substrate, and distribution: clarifying the major phylogenetic framework of Pluteus sect. Hispidoderma (Agaricales, Pluteaceae) and describing 18 species. IMA Fungus 16: e 154329, DOI: 10.3897/imafungus.16.154329
AE2047D258B65C19B2D85A8C69EA7448.taxon	description	Figs 5 J, K, 11	en	Qi, Zheng-Xiang, Wang, Li-Bo, Qian, Ke-Qing, Shi, Li-Li, Hu, Jia-Jun, Tuo, Yong-Lan, Rao, Gu, Samwel Jacob, Muharagi, Liu, Rui-Peng, Liu, Ming-Hao, Guo, Di-Zhe, Liu, Ya-Jie, Zhang, Bo, Li, Xiao, Li, Yu (2025): Integrating morphology, phylogeny, substrate, and distribution: clarifying the major phylogenetic framework of Pluteus sect. Hispidoderma (Agaricales, Pluteaceae) and describing 18 species. IMA Fungus 16: e 154329, DOI: 10.3897/imafungus.16.154329
AE2047D258B65C19B2D85A8C69EA7448.taxon	description	Description. Basidiomata medium-sized. Pileus 43 mm diam; hemispherical; charred yellow in the center, transitioning to light yellow (10 YR 9 / 2) to white (10 P 9 / 2) toward the margin; surface dry, or dehisce, slightly velvety; margin shorter grooves striate, and straight. Context pale yellow (2.5 Y 9 / 2). Lamellae free, 4 – 8 mm wide, crowded, white (10 P 9 / 2) to yellowish (2.5 Y 9 / 2), unequal, thin, ventricose, edges even or flocculose; lamellar edge white. Stipe 39 × 4 mm, fibrous, hollow, clavate, slightly curved at the base and inflated bulbous, with white mycelium close to the rotting wood, overall pale yellow (10 YR 9 / 2) with white (10 P 9 / 2) glandular dots on the surface. Spore print unknown. Basidiospores [40 / 1 / 1] 7.0 – 8.0 (– 8.5) × 6.0 – 6.5 (– 7.5) µm, avL × avW = 7.4 – 7.6 × 6.2 – 6.5 µm, Q = 1.07 – 1.21 µm, avQ = 1.10 – 1.15 µm, globose to subglobose, rarely broadly ellipsoid, smooth, slightly pinkish, thin-walled. Basidia 24 – 33 × 9 – 11 µm, clavate, thin-walled, 4 - sterigmate, hyaline. Pleurocystidia 53 – 80 × 15 – 35 μm, rare, scattered, fusiform to broadly subfusiform, or broadly clavate, apically obtuse, thin-walled, smooth, hyaline. Lamellar edge sterile. Cheilocystidia 33 – 61 × 12 – 18 μm, abundant, clustered, clavate or subfusiform, apically obtuse, thin-walled, hyaline. Pileipellis a hymeniderm, with terminal elements 70 – 105 × 18 – 29 μm, broadly subcylindric or subfusiform, thin-walled, with pale brown intracellular pigment. Stipitipellis a cutis, hyphae 4 – 6 μm diam, cylindrical, hyaline, thin-walled. Caulocystidia 43 – 73 × 12 – 22 μm, scattered to clustered, abundant, composed of clavate, fusiform, and broadly fusiform, most with bluntly rounded apices, a few with small apical projections, some containing brownish intracellular pigment, thin-walled, smooth. Clamp connections absent in all tissues.	en	Qi, Zheng-Xiang, Wang, Li-Bo, Qian, Ke-Qing, Shi, Li-Li, Hu, Jia-Jun, Tuo, Yong-Lan, Rao, Gu, Samwel Jacob, Muharagi, Liu, Rui-Peng, Liu, Ming-Hao, Guo, Di-Zhe, Liu, Ya-Jie, Zhang, Bo, Li, Xiao, Li, Yu (2025): Integrating morphology, phylogeny, substrate, and distribution: clarifying the major phylogenetic framework of Pluteus sect. Hispidoderma (Agaricales, Pluteaceae) and describing 18 species. IMA Fungus 16: e 154329, DOI: 10.3897/imafungus.16.154329
AE2047D258B65C19B2D85A8C69EA7448.taxon	distribution	World distribution. China.	en	Qi, Zheng-Xiang, Wang, Li-Bo, Qian, Ke-Qing, Shi, Li-Li, Hu, Jia-Jun, Tuo, Yong-Lan, Rao, Gu, Samwel Jacob, Muharagi, Liu, Rui-Peng, Liu, Ming-Hao, Guo, Di-Zhe, Liu, Ya-Jie, Zhang, Bo, Li, Xiao, Li, Yu (2025): Integrating morphology, phylogeny, substrate, and distribution: clarifying the major phylogenetic framework of Pluteus sect. Hispidoderma (Agaricales, Pluteaceae) and describing 18 species. IMA Fungus 16: e 154329, DOI: 10.3897/imafungus.16.154329
AE2047D258B65C19B2D85A8C69EA7448.taxon	distribution	China distribution. Jilin Province.	en	Qi, Zheng-Xiang, Wang, Li-Bo, Qian, Ke-Qing, Shi, Li-Li, Hu, Jia-Jun, Tuo, Yong-Lan, Rao, Gu, Samwel Jacob, Muharagi, Liu, Rui-Peng, Liu, Ming-Hao, Guo, Di-Zhe, Liu, Ya-Jie, Zhang, Bo, Li, Xiao, Li, Yu (2025): Integrating morphology, phylogeny, substrate, and distribution: clarifying the major phylogenetic framework of Pluteus sect. Hispidoderma (Agaricales, Pluteaceae) and describing 18 species. IMA Fungus 16: e 154329, DOI: 10.3897/imafungus.16.154329
B9E5F9BFD43B59F8986A3CE5B4CC9C66.taxon	description	Figs 5 H, I, 9	en	Qi, Zheng-Xiang, Wang, Li-Bo, Qian, Ke-Qing, Shi, Li-Li, Hu, Jia-Jun, Tuo, Yong-Lan, Rao, Gu, Samwel Jacob, Muharagi, Liu, Rui-Peng, Liu, Ming-Hao, Guo, Di-Zhe, Liu, Ya-Jie, Zhang, Bo, Li, Xiao, Li, Yu (2025): Integrating morphology, phylogeny, substrate, and distribution: clarifying the major phylogenetic framework of Pluteus sect. Hispidoderma (Agaricales, Pluteaceae) and describing 18 species. IMA Fungus 16: e 154329, DOI: 10.3897/imafungus.16.154329
B9E5F9BFD43B59F8986A3CE5B4CC9C66.taxon	etymology	Etymology. The species epithet “ spaniophyllus ” (Latin) refers to the sparseness of the lamellae.	en	Qi, Zheng-Xiang, Wang, Li-Bo, Qian, Ke-Qing, Shi, Li-Li, Hu, Jia-Jun, Tuo, Yong-Lan, Rao, Gu, Samwel Jacob, Muharagi, Liu, Rui-Peng, Liu, Ming-Hao, Guo, Di-Zhe, Liu, Ya-Jie, Zhang, Bo, Li, Xiao, Li, Yu (2025): Integrating morphology, phylogeny, substrate, and distribution: clarifying the major phylogenetic framework of Pluteus sect. Hispidoderma (Agaricales, Pluteaceae) and describing 18 species. IMA Fungus 16: e 154329, DOI: 10.3897/imafungus.16.154329
B9E5F9BFD43B59F8986A3CE5B4CC9C66.taxon	diagnosis	Diagnosis. Pluteus spaniophyllus differs from P. jilinensis by its velvety pileus, sparse lamellae, smaller basidiospores, and their ITS genetic distance is 0.008 (SE = 0.004) and tef 1 genetic distance is 0.008 (SE = 0.004).	en	Qi, Zheng-Xiang, Wang, Li-Bo, Qian, Ke-Qing, Shi, Li-Li, Hu, Jia-Jun, Tuo, Yong-Lan, Rao, Gu, Samwel Jacob, Muharagi, Liu, Rui-Peng, Liu, Ming-Hao, Guo, Di-Zhe, Liu, Ya-Jie, Zhang, Bo, Li, Xiao, Li, Yu (2025): Integrating morphology, phylogeny, substrate, and distribution: clarifying the major phylogenetic framework of Pluteus sect. Hispidoderma (Agaricales, Pluteaceae) and describing 18 species. IMA Fungus 16: e 154329, DOI: 10.3897/imafungus.16.154329
B9E5F9BFD43B59F8986A3CE5B4CC9C66.taxon	description	Description. Basidiomata small-sized. Pileus 17 mm diam; hemispherical; white to light yellow (2.5 Y 9 / 10), slightly with brown velvety or pruinose on the surface of the center (7.5 YR 8 / 6); margin radial translucently striate. Lamellae pale flesh – pink (5.0 R 9 / 6), free, relatively sparse, thick, unequal, slightly ventricose, 4 – 7 mm wide, with even edges; lamellar edge white. Stipe 14 × 3 mm, cylindrical, with a bulbous base, fibrous, surface with white pruinose (2.5 Y 9 / 12). Odorless. Spore prints pink. Basidiospores [60, 1, 1] (– 6.5) 7.0 – 7.5 (– 8.0) × 6.0 – 6.5 (– 7.0) μm, avL × avW = 7.0 – 7.3 × 6.2 – 6.5 µm, Q = 1.00 – 1.33 μm, avQ = 1.07 – 1.10 μm, globose, subglobose to broadly ellipsoid, pale pink, smooth, thin-walled. Basidia 23 – 30 × 8 – 11 μm, clavate to broadly clavate, thin-walled, 4 - sterigmate, hyaline. Pleurocystidia 53 – 91 × 18 – 31 μm, scattered, fusiform to subfusiform, apically obtuse, thin-walled, smooth, hyaline. Lamellar edge sterile. Cheilocystidia 25 – 70 × 11 – 27 μm, abundant, clustered, similar in form to pleurocystidia, narrowly to broadly fusiform, broadly subfusiform, some apical with small irregular horns or mucronate, thin-walled, hyaline. Pileipellis a trichohymeniderm, with terminal elements 51 – 92 × 12 – 28 μm, broadly clavate or fusiform, thin-walled, with brown intracellular pigment. Stipitipellis a cutis, hyphae 3 – 12 µm diam, cylindrical, hyaline, thin-walled. Caulocystidia 28 – 47 × 9 – 18 μm, numerous, occurring in clusters, cylindrical to broadly clavate to broadly fusiform, or narrowly utriform, hyaline, thin-walled. Clamp connections absent in all tissues.	en	Qi, Zheng-Xiang, Wang, Li-Bo, Qian, Ke-Qing, Shi, Li-Li, Hu, Jia-Jun, Tuo, Yong-Lan, Rao, Gu, Samwel Jacob, Muharagi, Liu, Rui-Peng, Liu, Ming-Hao, Guo, Di-Zhe, Liu, Ya-Jie, Zhang, Bo, Li, Xiao, Li, Yu (2025): Integrating morphology, phylogeny, substrate, and distribution: clarifying the major phylogenetic framework of Pluteus sect. Hispidoderma (Agaricales, Pluteaceae) and describing 18 species. IMA Fungus 16: e 154329, DOI: 10.3897/imafungus.16.154329
B9E5F9BFD43B59F8986A3CE5B4CC9C66.taxon	distribution	World distribution. China.	en	Qi, Zheng-Xiang, Wang, Li-Bo, Qian, Ke-Qing, Shi, Li-Li, Hu, Jia-Jun, Tuo, Yong-Lan, Rao, Gu, Samwel Jacob, Muharagi, Liu, Rui-Peng, Liu, Ming-Hao, Guo, Di-Zhe, Liu, Ya-Jie, Zhang, Bo, Li, Xiao, Li, Yu (2025): Integrating morphology, phylogeny, substrate, and distribution: clarifying the major phylogenetic framework of Pluteus sect. Hispidoderma (Agaricales, Pluteaceae) and describing 18 species. IMA Fungus 16: e 154329, DOI: 10.3897/imafungus.16.154329
B9E5F9BFD43B59F8986A3CE5B4CC9C66.taxon	distribution	China distribution. Jilin Province.	en	Qi, Zheng-Xiang, Wang, Li-Bo, Qian, Ke-Qing, Shi, Li-Li, Hu, Jia-Jun, Tuo, Yong-Lan, Rao, Gu, Samwel Jacob, Muharagi, Liu, Rui-Peng, Liu, Ming-Hao, Guo, Di-Zhe, Liu, Ya-Jie, Zhang, Bo, Li, Xiao, Li, Yu (2025): Integrating morphology, phylogeny, substrate, and distribution: clarifying the major phylogenetic framework of Pluteus sect. Hispidoderma (Agaricales, Pluteaceae) and describing 18 species. IMA Fungus 16: e 154329, DOI: 10.3897/imafungus.16.154329
174711C0FCBB5BF083A181F42DBFEA0D.taxon	description	Figs 5 A – D, 8	en	Qi, Zheng-Xiang, Wang, Li-Bo, Qian, Ke-Qing, Shi, Li-Li, Hu, Jia-Jun, Tuo, Yong-Lan, Rao, Gu, Samwel Jacob, Muharagi, Liu, Rui-Peng, Liu, Ming-Hao, Guo, Di-Zhe, Liu, Ya-Jie, Zhang, Bo, Li, Xiao, Li, Yu (2025): Integrating morphology, phylogeny, substrate, and distribution: clarifying the major phylogenetic framework of Pluteus sect. Hispidoderma (Agaricales, Pluteaceae) and describing 18 species. IMA Fungus 16: e 154329, DOI: 10.3897/imafungus.16.154329
174711C0FCBB5BF083A181F42DBFEA0D.taxon	etymology	Etymology. The species epithet “ tenuipileus ” (Latin) refers to the thin, flake-like pileus.	en	Qi, Zheng-Xiang, Wang, Li-Bo, Qian, Ke-Qing, Shi, Li-Li, Hu, Jia-Jun, Tuo, Yong-Lan, Rao, Gu, Samwel Jacob, Muharagi, Liu, Rui-Peng, Liu, Ming-Hao, Guo, Di-Zhe, Liu, Ya-Jie, Zhang, Bo, Li, Xiao, Li, Yu (2025): Integrating morphology, phylogeny, substrate, and distribution: clarifying the major phylogenetic framework of Pluteus sect. Hispidoderma (Agaricales, Pluteaceae) and describing 18 species. IMA Fungus 16: e 154329, DOI: 10.3897/imafungus.16.154329
174711C0FCBB5BF083A181F42DBFEA0D.taxon	diagnosis	Diagnosis. Morphologically similar to P. lauracearum, differing by its smooth and thin pileus, distinct ITS sequences (genetic distance = 0.021, SE = 0.006), and distribution in East Asia (China).	en	Qi, Zheng-Xiang, Wang, Li-Bo, Qian, Ke-Qing, Shi, Li-Li, Hu, Jia-Jun, Tuo, Yong-Lan, Rao, Gu, Samwel Jacob, Muharagi, Liu, Rui-Peng, Liu, Ming-Hao, Guo, Di-Zhe, Liu, Ya-Jie, Zhang, Bo, Li, Xiao, Li, Yu (2025): Integrating morphology, phylogeny, substrate, and distribution: clarifying the major phylogenetic framework of Pluteus sect. Hispidoderma (Agaricales, Pluteaceae) and describing 18 species. IMA Fungus 16: e 154329, DOI: 10.3897/imafungus.16.154329
174711C0FCBB5BF083A181F42DBFEA0D.taxon	description	Description. Basidiomata medium-sized. Pileus 17 – 33 mm diam; plano-convex, sometimes slightly depressed at the center; light grayish brown (2.5 YR 7 / 2) with white margins (2.5 YR 9 / 2); surface smooth to rarely white pruinose (2.5 YR 9 / 2), radial striate from the middle to the margin; margin pilcate, with umbrella-like teeth. Lamellae cream to flesh-pink (2.5 R 9 / 2 – 2.5 R 9 / 6), free, crowded, thick, unequal, ventricose, 3 – 5 mm wide, with even edges; lamellar edge white. Stipe 20 – 25 × 2 – 3 mm, cylindrical, white (2.5 R 9 / 2), base bulbous, fibrous and brittle bony, surface with white pruinose (2.5 R 9 / 2). Odorless. Spore prints pink. Basidiospores [120, 3, 2] 6.0 – 7.0 × 5.0 – 6.0 (– 6.5) μm, avL × avW = 6.4 – 6.6 × 5.5 – 5.7 µm, Q = 1.07 – 1.40 μm, avQ = 1.16 – 1.20 μm, subglobose to broadly ellipsoid or ovoid, slightly pinkish, smooth, thin-walled. Basidia 21 – 28 × 7 – 8 µm, clavate, thin-walled, 4 - sterigmate, hyaline. Pleurocystidia 53 – 93 × 24 – 32 μm, abundant, scattered, fusiform or subfusiform, apical portion with mucronate, rostrate with up to 2 – 6 μm long, thin-walled, smooth, hyaline. Lamellar edge sterile. Cheilocystidia 36 – 68 × 14 – 26 μm, abundant, clustered, narrowly clavate to clavate, or long clavate, obtusely rounded apically, short basally, thin-walled, hyaline. Pileipellis a trichohymeniderm, with terminal elements 58 – 95 × 15 – 30 μm, broadly clavate or fusiform, thin-walled, with brown intracellular pigment. Stipitipellis a cutis, hyphae 3 – 12 µm diam, cylindrical, hyaline, thin-walled. Caulocystidia 24 – 53 × 7 – 17 μm, numerous, occurring in clusters, cylindrical to broadly clavate to broadly fusiform, or narrowly utriform, hyaline, thin-walled. Clamp connections absent in all tissues.	en	Qi, Zheng-Xiang, Wang, Li-Bo, Qian, Ke-Qing, Shi, Li-Li, Hu, Jia-Jun, Tuo, Yong-Lan, Rao, Gu, Samwel Jacob, Muharagi, Liu, Rui-Peng, Liu, Ming-Hao, Guo, Di-Zhe, Liu, Ya-Jie, Zhang, Bo, Li, Xiao, Li, Yu (2025): Integrating morphology, phylogeny, substrate, and distribution: clarifying the major phylogenetic framework of Pluteus sect. Hispidoderma (Agaricales, Pluteaceae) and describing 18 species. IMA Fungus 16: e 154329, DOI: 10.3897/imafungus.16.154329
174711C0FCBB5BF083A181F42DBFEA0D.taxon	distribution	World distribution. China.	en	Qi, Zheng-Xiang, Wang, Li-Bo, Qian, Ke-Qing, Shi, Li-Li, Hu, Jia-Jun, Tuo, Yong-Lan, Rao, Gu, Samwel Jacob, Muharagi, Liu, Rui-Peng, Liu, Ming-Hao, Guo, Di-Zhe, Liu, Ya-Jie, Zhang, Bo, Li, Xiao, Li, Yu (2025): Integrating morphology, phylogeny, substrate, and distribution: clarifying the major phylogenetic framework of Pluteus sect. Hispidoderma (Agaricales, Pluteaceae) and describing 18 species. IMA Fungus 16: e 154329, DOI: 10.3897/imafungus.16.154329
174711C0FCBB5BF083A181F42DBFEA0D.taxon	distribution	China distribution. Jilin Province.	en	Qi, Zheng-Xiang, Wang, Li-Bo, Qian, Ke-Qing, Shi, Li-Li, Hu, Jia-Jun, Tuo, Yong-Lan, Rao, Gu, Samwel Jacob, Muharagi, Liu, Rui-Peng, Liu, Ming-Hao, Guo, Di-Zhe, Liu, Ya-Jie, Zhang, Bo, Li, Xiao, Li, Yu (2025): Integrating morphology, phylogeny, substrate, and distribution: clarifying the major phylogenetic framework of Pluteus sect. Hispidoderma (Agaricales, Pluteaceae) and describing 18 species. IMA Fungus 16: e 154329, DOI: 10.3897/imafungus.16.154329
8F3C092620B75652B6918F3DE7084A52.taxon	description	Figs 7 A – C, 12	en	Qi, Zheng-Xiang, Wang, Li-Bo, Qian, Ke-Qing, Shi, Li-Li, Hu, Jia-Jun, Tuo, Yong-Lan, Rao, Gu, Samwel Jacob, Muharagi, Liu, Rui-Peng, Liu, Ming-Hao, Guo, Di-Zhe, Liu, Ya-Jie, Zhang, Bo, Li, Xiao, Li, Yu (2025): Integrating morphology, phylogeny, substrate, and distribution: clarifying the major phylogenetic framework of Pluteus sect. Hispidoderma (Agaricales, Pluteaceae) and describing 18 species. IMA Fungus 16: e 154329, DOI: 10.3897/imafungus.16.154329
8F3C092620B75652B6918F3DE7084A52.taxon	etymology	Etymology. Derived from Latin ‘ ultra’ (extremely), ‘ putri’ (rotten), and ‘ piceae’ (of spruce), the species epithet “ ultraputripiceae ” characterizes the fungus’s distinctive ecological niche on severely decomposed spruce wood substrates.	en	Qi, Zheng-Xiang, Wang, Li-Bo, Qian, Ke-Qing, Shi, Li-Li, Hu, Jia-Jun, Tuo, Yong-Lan, Rao, Gu, Samwel Jacob, Muharagi, Liu, Rui-Peng, Liu, Ming-Hao, Guo, Di-Zhe, Liu, Ya-Jie, Zhang, Bo, Li, Xiao, Li, Yu (2025): Integrating morphology, phylogeny, substrate, and distribution: clarifying the major phylogenetic framework of Pluteus sect. Hispidoderma (Agaricales, Pluteaceae) and describing 18 species. IMA Fungus 16: e 154329, DOI: 10.3897/imafungus.16.154329
8F3C092620B75652B6918F3DE7084A52.taxon	diagnosis	Diagnosis. Pluteus ultraputripiceae is characterized by its brown to light flesh-brown pileus, broadly ellipsoid to ellipsoid basidiospores (avL × avW = 7.7 – 8.0 × 6.4 – 6.8 µm), pleurocystidia lacking apical excrescences. It differs from P. dianae by the absence of small apical excrescence structures at the top of pleurocystidia, substrate preference for highly decayed trunks, and distribution in East Asia (China). The ITS genetic distance is 0.040 (SE = 0.008).	en	Qi, Zheng-Xiang, Wang, Li-Bo, Qian, Ke-Qing, Shi, Li-Li, Hu, Jia-Jun, Tuo, Yong-Lan, Rao, Gu, Samwel Jacob, Muharagi, Liu, Rui-Peng, Liu, Ming-Hao, Guo, Di-Zhe, Liu, Ya-Jie, Zhang, Bo, Li, Xiao, Li, Yu (2025): Integrating morphology, phylogeny, substrate, and distribution: clarifying the major phylogenetic framework of Pluteus sect. Hispidoderma (Agaricales, Pluteaceae) and describing 18 species. IMA Fungus 16: e 154329, DOI: 10.3897/imafungus.16.154329
8F3C092620B75652B6918F3DE7084A52.taxon	description	Description. Basidiomata medium-sized. Pileus 27 – 47 mm diam; convex to slightly hemispherical when young, brown to dark brown (7.5 YR 5 / 4 - 10 YR 4 / 6); plano-convex to applanate at maturity, light flesh – brown (2.5 YR 9 / 6) to cinnamon-colored (2.5 YR 8 / 4) and smooth, with slightly translucently striate at the margin, crenulate. Lamellae creamy white (2.5 YR 8 / 6), free, crowded, thick, unequal, slightly ventricose, 6 – 9 mm wide, edges even; lamellar edge white. Stipe 31 – 55 × 5 – 7 mm, cylindrical, fibrous, with white longitudinal striate on the surface (2.5 YR 9 / 4). Odorless. Spore prints pink. Basidiospores [100, 7, 3] 7.0 – 8.0 (– 8.5) × 6.0 – 7.0 (– 7.5) μm, avL × avW = 7.7 – 8.0 × 6.4 – 6.8 µm, Q = 1.10 – 1.41 μm, avQ = 1.14 – 1.20 μm, broadly ellipsoid to ellipsoid, or ovoid, pale pink, smooth, thin-walled. Basidia 21 – 29 × 6 – 10 µm, clavate, thin-walled, 4 - sterigmate, hyaline. Pleurocystidia 54 – 102 × 20 – 36 μm, few, scattered, clavate to broadly clavate, or fusiform, apically obtusely rounded, thin-walled, smooth, hyaline. Lamellar edge sterile. Cheilocystidia 41 – 79 × 18 – 29 μm, abundant, clustered, fusiform to narrowly clavate to clavate, or broadly clavate, bluntly rounded apically, thin-walled, smooth, hyaline. Pileipellis a trichohymeniderm, with terminal elements 35 – 64 × 11 – 25 μm broadly clavate or fusiform, thin-walled, with brown intracellular pigment. Stipitipellis a cutis, hyphae 3 – 12 µm diam, cylindrical, hyaline, thin-walled. Caulocystidia 30 – 61 × 10 – 21 μm, numerous, occurring in clusters, cylindrical to broadly clavate to broadly fusiform, or narrowly utriform, apically obtusely rounded, smooth, thin-walled, with brown intracellular pigment. Clamp connections absent in all tissues.	en	Qi, Zheng-Xiang, Wang, Li-Bo, Qian, Ke-Qing, Shi, Li-Li, Hu, Jia-Jun, Tuo, Yong-Lan, Rao, Gu, Samwel Jacob, Muharagi, Liu, Rui-Peng, Liu, Ming-Hao, Guo, Di-Zhe, Liu, Ya-Jie, Zhang, Bo, Li, Xiao, Li, Yu (2025): Integrating morphology, phylogeny, substrate, and distribution: clarifying the major phylogenetic framework of Pluteus sect. Hispidoderma (Agaricales, Pluteaceae) and describing 18 species. IMA Fungus 16: e 154329, DOI: 10.3897/imafungus.16.154329
8F3C092620B75652B6918F3DE7084A52.taxon	distribution	World distribution. China.	en	Qi, Zheng-Xiang, Wang, Li-Bo, Qian, Ke-Qing, Shi, Li-Li, Hu, Jia-Jun, Tuo, Yong-Lan, Rao, Gu, Samwel Jacob, Muharagi, Liu, Rui-Peng, Liu, Ming-Hao, Guo, Di-Zhe, Liu, Ya-Jie, Zhang, Bo, Li, Xiao, Li, Yu (2025): Integrating morphology, phylogeny, substrate, and distribution: clarifying the major phylogenetic framework of Pluteus sect. Hispidoderma (Agaricales, Pluteaceae) and describing 18 species. IMA Fungus 16: e 154329, DOI: 10.3897/imafungus.16.154329
8F3C092620B75652B6918F3DE7084A52.taxon	distribution	China distribution. Xinjiang Uygur Autonomous Region.	en	Qi, Zheng-Xiang, Wang, Li-Bo, Qian, Ke-Qing, Shi, Li-Li, Hu, Jia-Jun, Tuo, Yong-Lan, Rao, Gu, Samwel Jacob, Muharagi, Liu, Rui-Peng, Liu, Ming-Hao, Guo, Di-Zhe, Liu, Ya-Jie, Zhang, Bo, Li, Xiao, Li, Yu (2025): Integrating morphology, phylogeny, substrate, and distribution: clarifying the major phylogenetic framework of Pluteus sect. Hispidoderma (Agaricales, Pluteaceae) and describing 18 species. IMA Fungus 16: e 154329, DOI: 10.3897/imafungus.16.154329
FD56B704813F5616A2FE299299C369EB.taxon	description	Figs 18 F – H, 21	en	Qi, Zheng-Xiang, Wang, Li-Bo, Qian, Ke-Qing, Shi, Li-Li, Hu, Jia-Jun, Tuo, Yong-Lan, Rao, Gu, Samwel Jacob, Muharagi, Liu, Rui-Peng, Liu, Ming-Hao, Guo, Di-Zhe, Liu, Ya-Jie, Zhang, Bo, Li, Xiao, Li, Yu (2025): Integrating morphology, phylogeny, substrate, and distribution: clarifying the major phylogenetic framework of Pluteus sect. Hispidoderma (Agaricales, Pluteaceae) and describing 18 species. IMA Fungus 16: e 154329, DOI: 10.3897/imafungus.16.154329
FD56B704813F5616A2FE299299C369EB.taxon	description	Description. Basidiomata medium-sized. Pileus 15 – 41 mm diam; plano-convex to convex; earthy yellow (2.5 Y 8 / 6), surface with black-brown (7.5 YR 3 / 2) recurved conical scales, denser in the middle forming a vein, becoming sparse toward the margin, margin straight and slightly crenulate. Context white (10 P 9 / 2), 3 – 6 mm thick. Lamellae free, 5 – 7 mm wide, crowded, white (10 P 9 / 2) to pink (7.5 RP 8 / 4), unequal, moderately thick, ventricose, edges even to flocculose and white. Stipe 21 – 76 × 5 – 9 mm, fibrous, solid, clavate, slightly expanded at the base, whitish overall (10 P 9 / 2), with brown (7.5 YR 4 / 4) glandular dots on the surface. Spore print unknown. Basidiospores [40 / 2 / 1] 5.5 – 6.5 (– 7.0) × 5.0 – 6.0 µm, avL × avW = 6.1 – 6.5 × 5.5 – 5.9 µm, Q = 1.18 – 1.30 µm, avQ = 1.20 – 1.25 µm, broadly ellipsoid to ellipsoid, smooth, slightly pinkish, thick-walled. Basidia 24 – 28 × 7 – 9 μm, clavate, thin-walled, 4 - sterigmate, hyaline. Pleurocystidia 58 – 82 × 21 – 35 μm, rare, scattered, fusiform to broadly fusiform, with shorter necks, thin-walled, smooth, hyaline. Lamellar edge sterile. Cheilocystidia 37 – 63 × 16 – 21 μm, abundant, clustered, similar to Pleurocystidia, fusiform, commonly mucronate, thin-walled, smooth, generally with brown intracellular pigment. Pileipellis a trichohymeniderm composed of narrowed fusiform and clavate elements, with terminal elements 71 – 155 (– 174) × 17 – 25 μm, often grouped in clusters, pointed towards the apex, with brown intracellular pigment, thin- or slightly thick-walled. Stipitipellis a cutis, hyphae 4 – 7 μm diam, cylindrical, hyaline, thin-walled. Without caulocystidia. Clamp connections absent in all tissues.	en	Qi, Zheng-Xiang, Wang, Li-Bo, Qian, Ke-Qing, Shi, Li-Li, Hu, Jia-Jun, Tuo, Yong-Lan, Rao, Gu, Samwel Jacob, Muharagi, Liu, Rui-Peng, Liu, Ming-Hao, Guo, Di-Zhe, Liu, Ya-Jie, Zhang, Bo, Li, Xiao, Li, Yu (2025): Integrating morphology, phylogeny, substrate, and distribution: clarifying the major phylogenetic framework of Pluteus sect. Hispidoderma (Agaricales, Pluteaceae) and describing 18 species. IMA Fungus 16: e 154329, DOI: 10.3897/imafungus.16.154329
FD56B704813F5616A2FE299299C369EB.taxon	distribution	World distribution. Russia (Malysheva et al. 2016), China (Hosen et al. 2018), Turkey (Kaygusuz et al. 2019).	en	Qi, Zheng-Xiang, Wang, Li-Bo, Qian, Ke-Qing, Shi, Li-Li, Hu, Jia-Jun, Tuo, Yong-Lan, Rao, Gu, Samwel Jacob, Muharagi, Liu, Rui-Peng, Liu, Ming-Hao, Guo, Di-Zhe, Liu, Ya-Jie, Zhang, Bo, Li, Xiao, Li, Yu (2025): Integrating morphology, phylogeny, substrate, and distribution: clarifying the major phylogenetic framework of Pluteus sect. Hispidoderma (Agaricales, Pluteaceae) and describing 18 species. IMA Fungus 16: e 154329, DOI: 10.3897/imafungus.16.154329
FD56B704813F5616A2FE299299C369EB.taxon	distribution	China distribution. Jilin Province.	en	Qi, Zheng-Xiang, Wang, Li-Bo, Qian, Ke-Qing, Shi, Li-Li, Hu, Jia-Jun, Tuo, Yong-Lan, Rao, Gu, Samwel Jacob, Muharagi, Liu, Rui-Peng, Liu, Ming-Hao, Guo, Di-Zhe, Liu, Ya-Jie, Zhang, Bo, Li, Xiao, Li, Yu (2025): Integrating morphology, phylogeny, substrate, and distribution: clarifying the major phylogenetic framework of Pluteus sect. Hispidoderma (Agaricales, Pluteaceae) and describing 18 species. IMA Fungus 16: e 154329, DOI: 10.3897/imafungus.16.154329
B6C6604DB203507D818DD2DA1D675417.taxon	description	Figs 18 D, E, 20	en	Qi, Zheng-Xiang, Wang, Li-Bo, Qian, Ke-Qing, Shi, Li-Li, Hu, Jia-Jun, Tuo, Yong-Lan, Rao, Gu, Samwel Jacob, Muharagi, Liu, Rui-Peng, Liu, Ming-Hao, Guo, Di-Zhe, Liu, Ya-Jie, Zhang, Bo, Li, Xiao, Li, Yu (2025): Integrating morphology, phylogeny, substrate, and distribution: clarifying the major phylogenetic framework of Pluteus sect. Hispidoderma (Agaricales, Pluteaceae) and describing 18 species. IMA Fungus 16: e 154329, DOI: 10.3897/imafungus.16.154329
B6C6604DB203507D818DD2DA1D675417.taxon	description	Description. Basidiomata large-sized. Pileus 50 – 52 mm diam; convex to hemispherical, with a low, broad umbo; surface reddish-brown (7.5 YR 7 / 8), distributed with granular tan (7.5 YR 5 / 10), dense and dark brown in the center (7.5 YR 5 / 14), forming vein-like striate; margin crenulate, with small rounded or blunt teeth. Lamellae reddish-brown (2.5 R 5 / 6), free, crowded, thick, unequal, slightly ventricose, 5 – 7 mm wide, with brown and even to flocculose edges; lamellar edge commonly with brown pigment. Stipe 43 – 48 × 5 – 8 mm, cylindrical, gradually thickening toward the base, fibrous, surface reddish-brown with tan granules (2.5 YR 6 / 10). Odorless. Spore prints pink. Basidiospores [200, 4, 1] 5.0 – 6.0 (– 7.0) × 4.5 – 5.0 μm, avL × avW = 5.8 – 6.0 × 5.3 – 5.6 µm, Q = 1.05 – 1.33 μm, avQ = 1.10 – 1.16 μm, subglobose to broadly ellipsoid, slightly pinkish, smooth, thin-walled. Basidia 26 – 30 × 6 – 10 μm, clavate, thin-walled, 4 - sterigmate, and hyaline. Pleurocystidia 55 – 90 × 22 – 37 μm, abundant, scattered, fusiform to lageniform, often with tapering apex, or mucronate, 5 – 17 μm long, thin-walled, smooth, hyaline. Lamellar edge sterile. Cheilocystidia 41 – 75 × 14 – 20 μm, numerous, clustered, subfusiform to fusiform, or ventricose, with small irregular apical horns, 4 – 13 μm long, thin-walled, generally with brown intracellular pigment. Pileipellis a trichohymeniderm composed of narrowed fusiform and clavate elements, with terminal elements (51 –) 62 – 170 (– 190) × 9 – 27 μm, often grouped in clusters, pointed towards the apex, with brown intracellular pigment, thin and smooth. Stipitipellis a cutis, hyphae 5 – 13 µm diam, cylindrical, hyaline, thin-walled. Caulocystidia 53 – 125 × 10 – 24 μm, numerous, usually in clusters, cylindrical to slightly narrowly lageniform, rounded at apex, with brown to pale brown intracellular pigment, slightly thick-walled. Clamp connections absent in all tissues.	en	Qi, Zheng-Xiang, Wang, Li-Bo, Qian, Ke-Qing, Shi, Li-Li, Hu, Jia-Jun, Tuo, Yong-Lan, Rao, Gu, Samwel Jacob, Muharagi, Liu, Rui-Peng, Liu, Ming-Hao, Guo, Di-Zhe, Liu, Ya-Jie, Zhang, Bo, Li, Xiao, Li, Yu (2025): Integrating morphology, phylogeny, substrate, and distribution: clarifying the major phylogenetic framework of Pluteus sect. Hispidoderma (Agaricales, Pluteaceae) and describing 18 species. IMA Fungus 16: e 154329, DOI: 10.3897/imafungus.16.154329
B6C6604DB203507D818DD2DA1D675417.taxon	distribution	World distribution. Denmark, Finland, Norway, Sweden (Heilmann-Clausen 2012), Germany (Krieglsteiner 2003; Ludwig 2007), Britain and Ireland (Orton 1986; Legon et al. 2005), Italy (Boccardo et al. 2008), Switzerland (Breitenbach and Kränzlin 1995), Netherlands (Vellinga 1990), Spain (Justo et al. 2011 a), Russia (Malysheva et al. 2016), Turkey (Kaygusuz et al. 2019), China (Xu 2016).	en	Qi, Zheng-Xiang, Wang, Li-Bo, Qian, Ke-Qing, Shi, Li-Li, Hu, Jia-Jun, Tuo, Yong-Lan, Rao, Gu, Samwel Jacob, Muharagi, Liu, Rui-Peng, Liu, Ming-Hao, Guo, Di-Zhe, Liu, Ya-Jie, Zhang, Bo, Li, Xiao, Li, Yu (2025): Integrating morphology, phylogeny, substrate, and distribution: clarifying the major phylogenetic framework of Pluteus sect. Hispidoderma (Agaricales, Pluteaceae) and describing 18 species. IMA Fungus 16: e 154329, DOI: 10.3897/imafungus.16.154329
B6C6604DB203507D818DD2DA1D675417.taxon	distribution	China distribution. Northeast, North, Northwest, Southwest China.	en	Qi, Zheng-Xiang, Wang, Li-Bo, Qian, Ke-Qing, Shi, Li-Li, Hu, Jia-Jun, Tuo, Yong-Lan, Rao, Gu, Samwel Jacob, Muharagi, Liu, Rui-Peng, Liu, Ming-Hao, Guo, Di-Zhe, Liu, Ya-Jie, Zhang, Bo, Li, Xiao, Li, Yu (2025): Integrating morphology, phylogeny, substrate, and distribution: clarifying the major phylogenetic framework of Pluteus sect. Hispidoderma (Agaricales, Pluteaceae) and describing 18 species. IMA Fungus 16: e 154329, DOI: 10.3897/imafungus.16.154329
22D64D1053745A6488B08770A4A2E274.taxon	description	Figs 25 A – E, 28	en	Qi, Zheng-Xiang, Wang, Li-Bo, Qian, Ke-Qing, Shi, Li-Li, Hu, Jia-Jun, Tuo, Yong-Lan, Rao, Gu, Samwel Jacob, Muharagi, Liu, Rui-Peng, Liu, Ming-Hao, Guo, Di-Zhe, Liu, Ya-Jie, Zhang, Bo, Li, Xiao, Li, Yu (2025): Integrating morphology, phylogeny, substrate, and distribution: clarifying the major phylogenetic framework of Pluteus sect. Hispidoderma (Agaricales, Pluteaceae) and describing 18 species. IMA Fungus 16: e 154329, DOI: 10.3897/imafungus.16.154329
22D64D1053745A6488B08770A4A2E274.taxon	description	Description. Basidiomata medium-sized. Pileus 28 – 35 mm diam; campanulate when young, surface orange-red (7.5 YR 8 / 16); plano-convex or convex when mature, bright yellow (2.5 Y 8 / 12), slightly brownish (10.0 YR 7 / 16); smooth, margin slightly translucently striate, with straight margin. Context dirty white (10.0 YR 9 / 4), odorless, 3 – 5 mm thick. Lamellae initially dirty white (10.0 YR 9 / 4), turning pink at maturity (10.0 YR 8 / 8), free, crowded, thick, unequal, slightly ventricose, 6 – 7 mm wide. Stipe 68 – 72 × 8 – 10 mm, cylindrical, hollow, partly spirally curled, slightly thicker at the base, fibrous, white to brown at the base (10.0 YR 9 / 10). Odorless. Spore prints pink. Basidiospores [210, 7, 4] 6.0 – 6.5 (– 7.0) × 5.0 – 5.5 (– 6.0) μm, avL × avW = 6.3 – 6.5 × 5.2 – 5.4 µm, Q = 1.09 – 1.40 μm, avQ = 1.18 – 1.24 μm, broadly ellipsoid to ovoid, slightly pinkish, smooth, thin-walled. Basidia 25 – 32 × 7 – 11 μm, clavate, thin-walled, 4 - sterigmate, and hyaline in KOH. Pleurocystidia 55 – 102 × 22 – 36 μm, numerous, scattered, fusiform to subfusiform, obtusely rounded apically, tapering basally, commonly provided with 1 – 2 digitiform excrescences at apex, thin-walled, smooth, hyaline. Lamellar edge sterile. Cheilocystidia 41 – 79 × 18 – 29 μm, abundant, clustered, subfusiform to fusiform, mostly apically mucronate to rostrate, 8 – 20 μm long, thin-walled, hyaline. Lamellar trama divergent. Pileipellis a trichoderm with radial hyphae, with terminal elements 62 – 143 × 14 – 29 μm, hyphae at the center extending outwards, with cylindrical or fusiform elements, thick-walled, with slightly tan intracellular pigment. Stipitipellis a cutis, hyphae 6 – 11 µm diam, cylindrical, hyaline, thin-walled. Caulocystidia absent. Clamp connections absent in all tissues.	en	Qi, Zheng-Xiang, Wang, Li-Bo, Qian, Ke-Qing, Shi, Li-Li, Hu, Jia-Jun, Tuo, Yong-Lan, Rao, Gu, Samwel Jacob, Muharagi, Liu, Rui-Peng, Liu, Ming-Hao, Guo, Di-Zhe, Liu, Ya-Jie, Zhang, Bo, Li, Xiao, Li, Yu (2025): Integrating morphology, phylogeny, substrate, and distribution: clarifying the major phylogenetic framework of Pluteus sect. Hispidoderma (Agaricales, Pluteaceae) and describing 18 species. IMA Fungus 16: e 154329, DOI: 10.3897/imafungus.16.154329
22D64D1053745A6488B08770A4A2E274.taxon	distribution	World distribution. Russian Far East (Justo et al. 2025), China.	en	Qi, Zheng-Xiang, Wang, Li-Bo, Qian, Ke-Qing, Shi, Li-Li, Hu, Jia-Jun, Tuo, Yong-Lan, Rao, Gu, Samwel Jacob, Muharagi, Liu, Rui-Peng, Liu, Ming-Hao, Guo, Di-Zhe, Liu, Ya-Jie, Zhang, Bo, Li, Xiao, Li, Yu (2025): Integrating morphology, phylogeny, substrate, and distribution: clarifying the major phylogenetic framework of Pluteus sect. Hispidoderma (Agaricales, Pluteaceae) and describing 18 species. IMA Fungus 16: e 154329, DOI: 10.3897/imafungus.16.154329
22D64D1053745A6488B08770A4A2E274.taxon	distribution	China distribution. Jilin Province.	en	Qi, Zheng-Xiang, Wang, Li-Bo, Qian, Ke-Qing, Shi, Li-Li, Hu, Jia-Jun, Tuo, Yong-Lan, Rao, Gu, Samwel Jacob, Muharagi, Liu, Rui-Peng, Liu, Ming-Hao, Guo, Di-Zhe, Liu, Ya-Jie, Zhang, Bo, Li, Xiao, Li, Yu (2025): Integrating morphology, phylogeny, substrate, and distribution: clarifying the major phylogenetic framework of Pluteus sect. Hispidoderma (Agaricales, Pluteaceae) and describing 18 species. IMA Fungus 16: e 154329, DOI: 10.3897/imafungus.16.154329
736E6338A1BE5868A96CAF3A6F8665C3.taxon	description	Figs 26 A – L, 30	en	Qi, Zheng-Xiang, Wang, Li-Bo, Qian, Ke-Qing, Shi, Li-Li, Hu, Jia-Jun, Tuo, Yong-Lan, Rao, Gu, Samwel Jacob, Muharagi, Liu, Rui-Peng, Liu, Ming-Hao, Guo, Di-Zhe, Liu, Ya-Jie, Zhang, Bo, Li, Xiao, Li, Yu (2025): Integrating morphology, phylogeny, substrate, and distribution: clarifying the major phylogenetic framework of Pluteus sect. Hispidoderma (Agaricales, Pluteaceae) and describing 18 species. IMA Fungus 16: e 154329, DOI: 10.3897/imafungus.16.154329
736E6338A1BE5868A96CAF3A6F8665C3.taxon	description	Description. Basidiomata small to medium-sized. Pileus 21 – 42 mm diam; campanulate to hemispherical when young, egg-yellow (5.0 Y 9 / 12); gradually plano-convex at maturity, bright yellow (5.0 Y 9 / 18), brown in the middle (7.5 YR 7 / 18); the white margin, with striate from the middle to the margin, straight. Context yellowish (2.5 Y 8 / 18), odorless, 2 – 4 mm thick. Lamellae initially white, becoming pink to flesh-pink at maturity (2.5 Y 9 / 12 – 2.5 Y 8 / 12), free, crowded, thick, unequal, 3 – 5 mm wide. Stipe 37 – 75 × 6 – 11 mm, cylindrical to compressed, hollow, white, fibrous, base light brown (2.5 Y 8 / 16), slightly thick to bulbous, surface relatively smooth. Odorless. Spore prints pink. Basidiospores [200, 12, 7] 5.0 – 5.5 (– 6.0) × 4.5 – 5.0 (– 5.5) μm, avL × avW = 5.2 – 5.5 × 4.8 – 5.0 µm, Q = 1.00 – 1.33 μm, avQ = 1.10 – 1.15 μm, spherical to subglobose, slightly pinkish, smooth, thin-walled. Basidia 24 – 30 × 7 – 10 μm, clavate, thin-walled, 4 - sterigmate, hyaline. Pleurocystidia 55 – 87 × 12 – 24 μm, scattered, fusiform, lageniform, or utriform, some with or without 1 – 2 digitiform excrescences at apex, thin-walled, smooth, hyaline. Lamellar edge sterile. Cheilocystidia 31 – 68 × 9 – 16 μm, numerous, clustered, subfusiform to fusiform, apically diverticulate or shortly rostrate, thin-walled, hyaline. Pileipellis a hymeniderm formed of variable and often mixed elements, from short and rounded to clavate or cylindrical terminal elements, 62 – 101 × 22 – 36 μm, with yellow intracellular pigment, with thin and smooth walls. Stipitipellis a cutis, hyphae 5 – 12 µm diam, cylindrical, hyaline, thin-walled. Caulocystidia 53 – 88 × 11 – 22 μm, mostly grouped, fusiform, lageniform to broadly lageniform, apical with short rostrate, thin-walled, smooth, hyaline. Clamp connections absent in all tissues.	en	Qi, Zheng-Xiang, Wang, Li-Bo, Qian, Ke-Qing, Shi, Li-Li, Hu, Jia-Jun, Tuo, Yong-Lan, Rao, Gu, Samwel Jacob, Muharagi, Liu, Rui-Peng, Liu, Ming-Hao, Guo, Di-Zhe, Liu, Ya-Jie, Zhang, Bo, Li, Xiao, Li, Yu (2025): Integrating morphology, phylogeny, substrate, and distribution: clarifying the major phylogenetic framework of Pluteus sect. Hispidoderma (Agaricales, Pluteaceae) and describing 18 species. IMA Fungus 16: e 154329, DOI: 10.3897/imafungus.16.154329
736E6338A1BE5868A96CAF3A6F8665C3.taxon	distribution	World distribution. Hungary (Babos 1978), Europe from Austria (Lohmeyer et al. 1994), Italy (Lanconelli et al. 1998; Migliozzi 2011; Lezzi et al. 2014), Romania (Béres 2012), Russia (as P. castri) (Justo et al. 2011 a), Slovenia (Jogan et al. 2012), Moldova (Lezzi et al. 2014), Japan (as P. castri) (Justo et al. 2011 a), Germany (Ludwig 2007), Turkey (Kaygusuz et al. 2019), China (as P. luteus) (Ševčíková and Dima 2021).	en	Qi, Zheng-Xiang, Wang, Li-Bo, Qian, Ke-Qing, Shi, Li-Li, Hu, Jia-Jun, Tuo, Yong-Lan, Rao, Gu, Samwel Jacob, Muharagi, Liu, Rui-Peng, Liu, Ming-Hao, Guo, Di-Zhe, Liu, Ya-Jie, Zhang, Bo, Li, Xiao, Li, Yu (2025): Integrating morphology, phylogeny, substrate, and distribution: clarifying the major phylogenetic framework of Pluteus sect. Hispidoderma (Agaricales, Pluteaceae) and describing 18 species. IMA Fungus 16: e 154329, DOI: 10.3897/imafungus.16.154329
736E6338A1BE5868A96CAF3A6F8665C3.taxon	distribution	China distribution. Henan Province, Sichuan Province, Jiangsu Province.	en	Qi, Zheng-Xiang, Wang, Li-Bo, Qian, Ke-Qing, Shi, Li-Li, Hu, Jia-Jun, Tuo, Yong-Lan, Rao, Gu, Samwel Jacob, Muharagi, Liu, Rui-Peng, Liu, Ming-Hao, Guo, Di-Zhe, Liu, Ya-Jie, Zhang, Bo, Li, Xiao, Li, Yu (2025): Integrating morphology, phylogeny, substrate, and distribution: clarifying the major phylogenetic framework of Pluteus sect. Hispidoderma (Agaricales, Pluteaceae) and describing 18 species. IMA Fungus 16: e 154329, DOI: 10.3897/imafungus.16.154329
9E5C6E2BB94B585383ECD6706F0E8163.taxon	description	Figs 6 H – J, 16	en	Qi, Zheng-Xiang, Wang, Li-Bo, Qian, Ke-Qing, Shi, Li-Li, Hu, Jia-Jun, Tuo, Yong-Lan, Rao, Gu, Samwel Jacob, Muharagi, Liu, Rui-Peng, Liu, Ming-Hao, Guo, Di-Zhe, Liu, Ya-Jie, Zhang, Bo, Li, Xiao, Li, Yu (2025): Integrating morphology, phylogeny, substrate, and distribution: clarifying the major phylogenetic framework of Pluteus sect. Hispidoderma (Agaricales, Pluteaceae) and describing 18 species. IMA Fungus 16: e 154329, DOI: 10.3897/imafungus.16.154329
9E5C6E2BB94B585383ECD6706F0E8163.taxon	description	Description. Basidiomata medium-sized. Pileus 11 – 37 mm diam; hemispherical to plano-convex, with obtuse umbo; surface fleshy brown (5 YR 6 / 4), slightly vein-like projections, margin indistinctly striped, inflexed. Context yellowish (7.5 P 9 / 2). Lamellae free, 3 – 6 mm wide, moderately crowded, flesh pink (5 R 9 / 2), unequal, with transvenose, thicker, slightly ventricose, edges even. Stipe 15 – 43 × 2 – 5 mm, rod-shaped, base expanded and slightly curved, fibrous, hollow, white (10 P 9 / 2) to light fleshy brown (7.5 YR 6 / 4). Spore print pink. Basidiospores [120 / 4 / 2] 5.5 – 6.5 × 5.0 – 5.5 (– 6.0) µm, avL × avW = 6.0 – 6.2 × 5.3 – 5.5 µm, Q = 1.09 – 1.30 µm, avQ = 1.15 – 1.20 µm, subglobose to broadly ellipsoid, smooth, slightly pinkish, thin-walled. Basidia 25 – 31 × 9 – 10 μm, clavate, thin-walled, 4 - sterigmate, hyaline. Pleurocystidia 55 – 78 × 14 – 25 μm, few, scattered, long fusiform to subfusiform, with a long neck and a conspicuous transverse septum, one part apically mucronate, the other bluntly rounded, thin-walled, smooth, a few containing brown intracellular pigment. Lamellar edge sterile. Cheilocystidia 33 – 61 × 12 – 18 μm, abundant, clustered, two forms, one long fusiform with a long neck (7 – 13 μm), the other apically expanded fusiform, thin-walled, smooth, hyaline. Pileipellis a trichoderm or trichohymeniderm, with terminal elements 71 – 145 × 21 – 26 μm, long clavate, subcylindric or subfusiform, thin-walled, with brown intracellular pigment. Stipitipellis a cutis, hyphae 4 – 7 μm diam, cylindrical, hyaline, thin-walled. Caulocystidia 29 – 49 × 12 – 21 μm, clustered, composed of irregular clavate, subcylindrical or sublageniform, partly containing brownish intracellular pigment, thin-walled, smooth. Clamp connections absent in all tissues.	en	Qi, Zheng-Xiang, Wang, Li-Bo, Qian, Ke-Qing, Shi, Li-Li, Hu, Jia-Jun, Tuo, Yong-Lan, Rao, Gu, Samwel Jacob, Muharagi, Liu, Rui-Peng, Liu, Ming-Hao, Guo, Di-Zhe, Liu, Ya-Jie, Zhang, Bo, Li, Xiao, Li, Yu (2025): Integrating morphology, phylogeny, substrate, and distribution: clarifying the major phylogenetic framework of Pluteus sect. Hispidoderma (Agaricales, Pluteaceae) and describing 18 species. IMA Fungus 16: e 154329, DOI: 10.3897/imafungus.16.154329
9E5C6E2BB94B585383ECD6706F0E8163.taxon	distribution	World distribution. India, Brazil, Mongolia, Russia, Italy (Malysheva et al. 2016; Ferisin and Dovana 2018), China.	en	Qi, Zheng-Xiang, Wang, Li-Bo, Qian, Ke-Qing, Shi, Li-Li, Hu, Jia-Jun, Tuo, Yong-Lan, Rao, Gu, Samwel Jacob, Muharagi, Liu, Rui-Peng, Liu, Ming-Hao, Guo, Di-Zhe, Liu, Ya-Jie, Zhang, Bo, Li, Xiao, Li, Yu (2025): Integrating morphology, phylogeny, substrate, and distribution: clarifying the major phylogenetic framework of Pluteus sect. Hispidoderma (Agaricales, Pluteaceae) and describing 18 species. IMA Fungus 16: e 154329, DOI: 10.3897/imafungus.16.154329
9E5C6E2BB94B585383ECD6706F0E8163.taxon	distribution	China distribution. Hubei Province (Wang JF 2019), Jilin Province.	en	Qi, Zheng-Xiang, Wang, Li-Bo, Qian, Ke-Qing, Shi, Li-Li, Hu, Jia-Jun, Tuo, Yong-Lan, Rao, Gu, Samwel Jacob, Muharagi, Liu, Rui-Peng, Liu, Ming-Hao, Guo, Di-Zhe, Liu, Ya-Jie, Zhang, Bo, Li, Xiao, Li, Yu (2025): Integrating morphology, phylogeny, substrate, and distribution: clarifying the major phylogenetic framework of Pluteus sect. Hispidoderma (Agaricales, Pluteaceae) and describing 18 species. IMA Fungus 16: e 154329, DOI: 10.3897/imafungus.16.154329
