Pluteus piceicola Z. X. QI, B. Zhang & Y. Li, 2025

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, pp. e 154329-e 154329 : e154329-

Pluteus piceicola Z. X. QI, B. Zhang & Y. Li sp. nov.

Figs 23 A – K , 24 A – M , 27

Etymology.

The species epithet “ piceicola ” (Latin) refers to its habitat on Picea schrenkiana .

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).

Holotype.

CHINA • Xinjiang Uygur Autonomous Region, Ili Kazakh Autonomous Prefecture, Tekes County, Jongkushtai village , 42°97'26.51"N, 82°12'77.25"E, alt. 2242 m, 3 September 2023, Z. X. Qi, FJAU 66574 (ITS: PP 516599 , LSU: PP 516651 , tef 1: PP 551589 ) (Collection no.: Qi 2849).

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.

Habitat.

Solitary or scattered on decaying dead wood in spruce forests ( P. schrenkiana ).

World distribution.

China.

China distribution.

Xinjiang Uygur Autonomous Region.

Other specimens examined.

CHINA • Xinjiang Uygur Autonomous Region, Ili Kazakh Autonomous Prefecture, Tekes County, Jongkushtai village . Scattered on rotting wood in spruce forests ( P. schrenkiana ); 42°17'62.61"N, 82°51'98.22"E, alt. 2236 m, 19 July 2023, Z. X. Qi, FJAU 66569 (Collection no.: Qi 498) (ITS: PP 516594 , LSU: PP 516646 , tef 1: PP 551584 ) . CHINA • Xinjiang Uygur Autonomous Region, Ili Kazakh Autonomous Prefecture, Tekes County, Jongkushtai village ; Solitary on rotting wood in spruce forests ( P. schrenkiana ); 42°19'62.68"N, 82°51'91.82"E, alt. 2128 m, 23 July 2023, Z. X. Qi, FJAU 66570 (Collection no.: Qi 632) (ITS: PP 516595 , LSU: PP 516647 , tef 1: PP 551585 ) . CHINA • Xinjiang Uygur Autonomous Region, Ili Kazakh Autonomous Prefecture, Tekes County, Jongkushtai village ; Scattered on rotting wood in spruce forests ( P. schrenkiana ); 42°15'68.67"N, 82°79'93.88"E, alt. 2224 m, 2 August 2023, Z. X. Qi, FJAU 66571 (Collection no.: Qi 840) (ITS: PP 516596 , LSU: PP 516648 , tef 1: PP 551586 ) . CHINA • Xinjiang Uygur Autonomous Region, Ili Kazakh Autonomous Prefecture, Tekes County, Jongkushtai village ; Solitary on rotting wood in spruce forests ( P. schrenkiana ); 42°15'11.73"N, 82°59'52.78"E, alt. 2318 m, 15 August 2023, Z. X. Qi, FJAU 66572 (Collection no.: Qi 2125) (ITS: PP 516597 , LSU: PP 516649 , tef 1: PP 551587 ) . CHINA • Xinjiang Uygur Autonomous Region, Ili Kazakh Autonomous Prefecture, Tekes County, Jongkushtai village ; Solitary on rotting wood in spruce forests ( P. schrenkiana ), 42°19'18.93"N, 82°58'22.18"E, alt. 2241 m, 27 August 2023, Z. X. Qi, FJAU 66573 (Collection no.: Qi 2584) (ITS: PP 516598 , LSU: PP 516650 , tef 1: PP 551588 ) . CHINA • Xinjiang Uygur Autonomous Region, Ili Kazakh Autonomous Prefecture, Tekes County, Jongkushtai village ; Solitary on rotting wood in spruce forests ( P. schrenkiana ); 42°15'28.45"N, 82°55'22.78"E, alt. 2169 m, 5 September 2023, Z. X. Qi, FJAU 66575 (Collection no.: Qi 2925) (ITS: PP 516600 , LSU: PP 516652 , tef 1: PP 551590 ) . CHINA • Xinjiang Uygur Autonomous Region, Ili Kazakh Autonomous Prefecture, Tekes County, Jongkushtai village ; Solitary on rotting wood in spruce forests ( P. schrenkiana ); 42°15'27.07"N, 82°55'22.66"E, alt. 2487 m, 15 June 2024, Z. X. Qi, FJAU 66601 (Collection no.: Qi 3179) (ITS: PQ 810770 , LSU: PQ 810747 , tef 1: PQ 811053 ) . CHINA • Xinjiang Uygur Autonomous Region, Ili Kazakh Autonomous Prefecture, Tekes County, Jongkushtai village ; Solitary on rotting wood in spruce forests ( P. schrenkiana ); 42°15'28.32"N, 82°55'21.28"E, alt. 2441 m, 23 June 2024, Z. X. Qi, FJAU 66602 (Collection no.: Qi 3321) (ITS: PQ 810771 , LSU: PQ 810748 , tef 1: PQ 811054 ) . CHINA • Xinjiang Uygur Autonomous Region, Ili Kazakh Autonomous Prefecture, Tekes County, Jongkushtai village ; Solitary on rotting wood in spruce forests ( P. schrenkiana ); 42°15'27.29"N, 82°55'22.80"E, alt. 2159 m, 27 June 2024, Z. X. Qi, FJAU 66603 (Collection no.: Qi 3383) (ITS: PQ 810772 , LSU: PQ 810749 , tef 1: PQ 811055 ) . CHINA • Xinjiang Uygur Autonomous Region, Ili Kazakh Autonomous Prefecture, Tekes County, Jongkushtai village ; Solitary on rotting wood in spruce forests ( P. schrenkiana ); 42°15'28.77"N, 82°55'20.35"E, alt. 2432 m, 27 June 2024, Z. X. Qi, FJAU 66604 (Collection no.: Qi 3387) (ITS: PQ 810773 , LSU: PQ 810750 , tef 1: PQ 811056 ) . CHINA • Xinjiang Uygur Autonomous Region, Ili Kazakh Autonomous Prefecture, Tekes County, Jongkushtai village ; Solitary on rotting wood in spruce forests ( P. schrenkiana ); 42°15'27.77"N, 82°55'22.75"E, alt. 2333 m, 10 July 2024, Z. X. Qi, FJAU 66605 (Collection no.: Qi 3631) (ITS: PQ 810774 , LSU: PQ 810751 , tef 1: PQ 811057 ) . CHINA • Xinjiang Uygur Autonomous Region, Ili Kazakh Autonomous Prefecture, Tekes County, Jongkushtai village ; Solitary on rotting wood in spruce forests ( P. schrenkiana ); 42°15'28.50"N, 82°55'23.60"E, alt. 2511 m, 11 July 2024, Z. X. Qi, FJAU 66606 (Collection no.: Qi 3668) (ITS: PQ 810775 , LSU: PQ 810752 , tef 1: PQ 811058 ) . CHINA • Xinjiang Uygur Autonomous Region, Ili Kazakh Autonomous Prefecture, Tekes County, Jongkushtai village ; Solitary on rotting wood in spruce forests ( P. schrenkiana ); 42°15'27.32"N, 82°55'22.66"E, alt. 2493 m, 20 July 2024, Z. X. Qi, FJAU 66607 (Collection no.: Qi 3961) (ITS: PQ 810776 , LSU: PQ 810753 , tef 1: PQ 811059 ) . CHINA • Xinjiang Uygur Autonomous Region, Ili Kazakh Autonomous Prefecture, Tekes County, Jongkushtai village ; Solitary on rotting wood in spruce forests ( P. schrenkiana ); 42°15'28.47"N, 82°55'22.55"E, alt. 2182 m, 2 August 2024, Z. X. Qi, FJAU 66608 (Collection no.: Qi 4133) (ITS: PQ 810777 , LSU: PQ 810754 , tef 1: PQ 811060 ) . CHINA • Xinjiang Uygur Autonomous Region, Ili Kazakh Autonomous Prefecture, Tekes County, Jongkushtai village ; Solitary on rotting wood in spruce forests ( P. schrenkiana ); 42°15'28.71"N, 82°55'22.44"E, alt. 2362 m, 30 August 2024, Z. X. Qi, FJAU 66609 (Collection no.: Qi 4849) (ITS: PQ 810778 , LSU: PQ 810755 , tef 1: PQ 811061 ) . CHINA • Xinjiang Uygur Autonomous Region, Ili Kazakh Autonomous Prefecture, Tekes County, Jongkushtai village ; Solitary on rotting wood in spruce forests ( P. schrenkiana ); 42°15'28.20"N, 82°55'22.49"E, alt. 2251 m, 30 August 2024, Z. X. Qi, FJAU 66610 (Collection no.: Qi 4856) (ITS: PQ 810779 , LSU: PQ 810756 , tef 1: PQ 811062 ) .

Notes.

Pluteus piceicola is characterized by its orange-yellow pileus with brown pruinose surface and distinctive spiral longitudinal stripes on the stipe. This species is associated with decaying wood in coniferous forests, specifically Picea schrenkiana , and is distributed in East Asia ( China).

Morphologically, P. piceicola may be confused with other Pluteus species exhibiting yellow to bright orange-yellow pileus. P. piceicola is distinguished from P. leoninus by its brown pruinose pileus surface, substrate preference for decaying woody branches in coniferous forests. In contrast, P. leoninus inhabits well-decayed wood of angiosperms (e. g., Betula , Carpinus , Fagus , Quercus ), is occasionally terrestrial under hardwoods, and rarely occurs on conifer wood ( Abies ) ( Kaygusuz et al. 2019; Justo et al. 2025). P. piceicola differs from P. ussuriensis primarily by its rougher, brown pruinose pileus surface, compared to the smoother pileus of the latter. This morphological distinction is supported by genetic distances of 0.034 (SE = 0.008) for ITS and 0.095 (SE = 0.016) for tef 1 ( Justo et al. 2025).

P. piceicola can be separated from P. admirabilis and P. chrysophaeus by its predominantly white stipe versus the yellow to yellowish stipe of the latter taxa, as well as by pileipellis structure: trichoderm in P. piceicola versus hymeniderm in the latter species ( Takehashi and Kasuya 2007; Menolli and Capelari 2010).

P. piceicola shares similarities with P. favrei , both exhibiting yellow to yellow-brown pileus, cheilocystidia with irregular or branched rostra, and a preference for decaying wood in Picea forests. However, P. piceicola produces smaller basidiospores (avL × avW = 7.4–7.6 × 5.6–6.0 µm) and lacks caulocystidia, while P. favrei forms larger basidiospores (avL × avW = 7.4–7.8 × 6.0–6.7 µm) and possesses caulocystidia (observed in the type collection). These taxa are further differentiated by genetic distances of 0.023 (SE = 0.006) for ITS and 0.078 (SE = 0.014) for tef 1 ( Justo et al. 2025).

Phylogenetically, P. piceicola is firmly positioned within the / leoninus clade with strong statistical support (MLB = 100, BPP = 1, Fig. 4 ), forming a distinct branch with distant affinities to morphologically similar species such as P. favrei , P. ussuriensis , and P. leoninus .

Figures

Figure 4. Phylogenetic tree of the / leoninus clade of the sect. Hispidoderma. The best tree from the ML and BI analysis of the ITS + tef 1 dataset. The two values of internal nodes respectively represent the Maximum Likelihood bootstrap (MLBP) / Bayesian posterior probability (BIPP). Nodes with a bootstrap probability (BP) ≥ 80 and a Bayesian posterior probability (PP) ≥ 0.80 are indicated in the phylogram. This study species is in bold and red font.

Figure 23. Basidiomata features. A – K. Pluteus piceicola (A, B. FJAU 66574, C. FJAU 66569, D, E. FJAU 66575, F, G. FJAU 66571, H, I. FJAU 66573, J, K. FJAU 66572). A – K. Photos by Zheng-Xiang Qi. Scale bars: 1 cm.

Figure 24. Basidiomata features. A – M. Pluteus piceicola (A, B. FJAU 66603, C, M. FJAU 66607, D, G. FJAU 66605, E, F. FJAU 66606, H, I. FJAU 66608, J. FJAU 66610, K, L. FJAU 66609). A – M. Photos by Zheng-Xiang Qi. Scale bars: 1 cm.

Figure 27. A. Macroscopic characteristics of Pluteus piceicola. B. Basidiospores. C. Pleurocystidia. D. Basidia and Pleurocystidia. E. Cheilocystidia. F. Pileipellis elements. Scale bars: 1 cm (A); 10 µm (B – E); 20 µm (F).