683 MycoKeys MycoKeys 104: 91-112 (2024) DOI: 10.3897/mycokeys.104.117841 Research Article New species, new records and common species of Pluteus sect. Celluloderma from northern China Zheng-Xiang Qi'® Ke-Qing Qian™®, Lei Yue’, Li-Bo Wang, Di-Zhe Guo’, Dong-Mei Wu’, Neng Gao’, Bo Zhang"®, Yu Li’ 1 Engineering Research Center of Edible and Medicinal Fungi, Ministry of Education, Jilin Agricultural University, Changchun, Jilin 130118, Changchun, China 2 Biotechnology Research Institute, Xinjiang Academy of Agricultural and Reclamation Sciences, Shihezi 830011, China Corresponding authors: Bo Zhang (zhangbofungi@126.com); Yu Li (yuli996@126.com) OPEN Qaceess Academic editor: S. C. Karunarathna Received: 26 December 2023 Accepted: 16 March 2024 Published: 16 April 2024 Citation: Qi Z-X, Qian K-Q, Yue L, Wang L-B, Guo D-Z, Wu D-M, Gao N, Zhang B, Li Y (2024) New species, new records and common species of Pluteus sect. Celluloderma from northern China. In: Wijayawardene N, Karunarathna S, Fan X-L, Li Q-R (Eds) Taxonomy and secondary metabolites of wood-associated fungi. MycoKeys 104: 91-112. https://doi.org/10.3897/ mycokeys.104.117841 Copyright: © Zheng-Xiang Qi et al. This is an open access article distributed under terms of the Creative Commons Attribution License (Attribution 4.0 International - CC BY 4.0). Abstract Wood-rotting fungi are organisms that can decompose wood substrates and extract nu- trients from them to support their growth. They play a crucial role in the material cycle of forest ecosystems. The genus Pluteus plays a significant role in wood decomposition. In this study, the morphology and molecular systematics of the sect. Cel/luloderma of the genus Pluteus were carried out. Pluteus brunneodiscus was identified as a new species, along with the discovery of two new records, P cystidiosus and P. chrysophlebius, and a common species, P romellii. Pluteus brunneodiscus is characterized by the brown cen- ter of the pileus that transitions to white towards the margins, with the surface cracking to form irregular granules. It is typically found in Populus forests growing on decompos- ing twigs or wood chips. Line drawings, color photographs, and phylogenetic analyses of related species within the genus Pluteus accompany the descriptions of these four species. The analyses are based on ITS + TEF1-a sequence data. Finally, a key for the twenty species within the sect. Cel/luloderma of the genus Pluteus, which has been doc- umented in China, is provided. Key words: Line drawings, morphology, phylogeny, wood-rotting fungi Introduction The genus Pluteus Fr., which belongs to the Basidiomycota, Agaricomycetes, Agaricales, Pluteaceae, was established by Fries in 1863. The genus Pluteus is characterized by its free lamellae, pinkish spore print, inverse hymenophoral trama, smooth spherical to ellipsoidal basidiospores, various forms of pleuro- cystidia, and often cheilocystidia. It is predominantly found on decaying wood and has a global distribution (Vellinga and Schreurs 1985; Singer 1986; Justo et al. 2011a, 2011b). The genus Pluteus was categorized into three sections based on the charac- teristics of the cystidia and pileipellis viz. (1) sect. Pluteus Fr is characterized by the existence of a cutis pileipellis and thick-walled pleurocystidia, (2) sect. Hispidoderma Fayod is characterized by a pileipellis that is a trichoderm com- posed of elongated cells and thin-walled pleurocystidia and (3) sect. Celluloder- ma Fayod is characterized by a pileipellis that is a hymeniderm or hymeniderm 91 Zheng-Xiang Qi et al.: New species, newly recorded and common species of Pluteus sect. Celluloderma with cystidioid elements, comprising of clavate to spheropedunculate cells and thin-walled pleurocystidia (Lange 1917; Imai 1938; Singer 1956). Molecular phy- logenetic analysis provides support for three sections (Pluteus Fr, Hispidoderma Fayod, and Celluloderma Fayod) (Menolli et al. 2010; Justo et al. 2011a, 2011b). Singer further subdivided Pluteus sect. Celluloderma into two subsections based on the composition of the pileipellis: subsect. Mixtini Singer, is charac- terized by elongated elements, and subsect. Eucellulodermini Singer is char- acterized by the absence of such elements (Singer 1956; Singer 1958). The molecular phylogenetic studies do not divide the Pluteus sect. Celluloderma into two subsections (Justo et al. 2011b). Some species belonged to the sect. Celluloderma (e.g., P ephebeus (Fr.) Gillet and related species). Based on their characteristics, species composed of non-metuloid cystidia and a pileipellis as cutis should belong to the sect. Hispidoderma. This is not consistent with the phylogenetic results. Thus, the classification of the two subsections of sect. Celluloderma needs to be further justified. Vellinga and Schreurs (1985) proposed a different taxonomic system to dis- tinguish these species (e.g., P ephebeus (Fr.) Gillet and related species), divid- ing the Pluteus sect. Celluloderma into three subsects, Mixtini, Eucelullodermini, and Hispidodermini (Fayod) Vellinga and Schreurs. The latter is characterized by a trichodermal pileipellis or a euhymeniderm consisting of cylindrical to fu- siform elements, which are similar to some of the characteristics of the sect. Hispidoderma. Additionally, Schreurs and Vellinga proposed a new group sect. Villosi Schreurs and Vellinga, containing species with a cutis-like pileipellis and non-metuloid (Singer 1958; Singer 1986). The proposed new sections and sub- sections by Singer (1958, 1986), Vellinga, and Schreurs (1985) lack support from molecular systematic studies (Justo et al. 2011a; Justo et al. 2012). Recent studies (Minnis et al. 2006; Menolli et al. 2010; Justo et al. 2011a, 201 1b; Vizzini and Ercole 2011) have indicated that sect. Celluloderma includes species characterized by the presence of non-metuloid pleurocystidia and a pileipellis that is either euhymeniderm or epithelioid hymeniderm, composed of short elements, which may or may not be intermixed or not with elongate cystidioid elements (corresponding to Pluteus sect. Celluloderma as defined by Singer 1956, 1958, 1986), refers to species with a cutis-like pileipellis and non-metuloid cystidia (corresponding to Pluteus sect. Villosi or Hispidoderma sensu Singer p.p.). In the current investigation, a new species, (P brunneodiscus), two new re- cords to China, (P chrysophlebius and P. cystidiosus), and a common species, (P romellii) are described. Detailed descriptions and illustrations are provided for the four species, along with clarification of the phylogenetic relationships of the identified species and related taxa from the genus Pluteus sect. Celluloderma. Materials and methods Morphology In the field, photographs of fresh basidiomata were taken to scientifically and adequately reflect the growing environment and characteristics of the basidi- omata, including the shape of the pileus, the color of the lamellae, and Munsell Soil Color Chart was followed for color codes (Munsell 2009). For fresh basidi- MycoKeys 104: 91-112 (2024), DOI: 10.3897/mycokeys.104.117841 92 Zheng-Xiang Qi et al.: New species, newly recorded and common species of Pluteus sect. Celluloderma omata, we promptly determined the size and recorded in detail the shape, size, color, odor, and other macroscopic characteristics of the basidiomata pileus, lamellae, and stipes. About 15 g of fresh context and lamellae were dried in a Ziplock bag with silica gel and returned to the lab for DNA extraction. Fresh basidiomata were dried at 40 ~ 45 °C (Huet al. 2022), using a plant drying oven and preserved in the fungarium of Jilin Agricultural University (FJAU). The observation of microstructural features was based on dried specimens. The dry specimens were rehydrated in 94% ethanol for microscopic examination and then mounted in 3% potassium hydroxide (KOH), 1% Congo Red, and Mel- zer’s Reagent, using a light microscope (ZEISS, DM1000, Oberkochen, Germany). Specifically, the following symbols were used in the description: [n/m/p] indi- cates that ‘n’ randomly selected basidiospores from ‘m’ basidiomata of ‘p’ col- lections were measured, ‘avl’ means the average length of basidiospores, except for the extreme values, ‘avw’ refers to the average width of the basidiospores, except the extreme values, ‘Q’ represents the quotient of the length and width of a single basidiospore inside view, ‘Qm’ refers to the average Q value of all basidiospores + standard deviation. The dimensions for basidiospores are given as (a)b-c(d). The range of b-c contains a minimum of 90% of the measured values. Extreme values (i.e., a and b) are given in parentheses (Qi et al. 2022). Molecular phylogeny DNA extraction, PCR amplification, and sequencing According to the instructions, the total DNA of the specimens was extracted by the new plant genomic DNA extraction kit from Jiangsu Kangwei Century Biotechnology Limited Company, P.R. China. Subsequently, sequences of the internal transcribed spacer (ITS) region, and translation elongation factor 1-a (TEF1-a) were used for phylogenetic analyses. The amplification primers of the nr ITS: ITS1-5.8S-ITS2 regions were ITS1F and ITS4/ITS4B (White et al. 1990), and TEF1-a regions were EF1—983F and EF1-1567R (Rehner and Buckley 2005). The amplification reactions were carried out in a 25 uL system. The total amount of PCR mixed was as follows: dd H,O 13.5 pL, 10 x Taq Buffer 5 uL, 10 mM dNTPs 1 uL, 10 mM upstream primer 1 uL, 10 mM downstream primer 1 uL, DNA sample 2 uL, 2 U/mm Taq Polymerase 1.5 tL. The cycle parameters were as follows: 5 min at 98 °C; 30 s at 98 °C, 30s at 55 °C, 1 min at 72 °C for 40 cycles; 7 min at 72 °C; storage at 4 °C (Sevcikova et al. 2022). The PCR product was subjected to 1% agarose gel electrophoresis. The purified PCR products were sent to Sangon Biotech Limited Company, P.R. China for sequencing using the Sanger method. The sequencing results were clipped with Seqman 7.1.0 (Swindell and Plasterer 1997) and subsequently deposited in GenBank (https:// www.ncbi.nim.nih.gov/genbank). Data analysis The species that were morphologically similar to new species, newly recorded species, and common species, and have high sequence similarity after blast were selected (Justo et al. 2011b, 2012; Menolli et al. 2015; Desjardin and Perry 2018; Hosen et al. 2019; Hosen et al. 2021; Sevéikova et al. 2022; Qi et al. 2022; MycoKeys 104: 91-112 (2024), DOI: 10.3897/mycokeys.104.117841 93 Zheng-Xiang Qi et al.: New species, newly recorded and common species of Pluteus sect. Celluloderma Table 1. Names, collection numbers, reported countries and corresponding GenBank accession numbers of the taxa used in this study. Taxon Pluteus absconditus P absconditus P. aff. ephebeus P. aff. ephebeus P aff. ephebeus P. aff. ephebeus P. aff. ephebeus P aletaiensis P aletaiensis P aurantiorugosus P aurantiorugosus P. austrofulvus P austrofulvus P. brunneidiscus P. brunneidiscus P cervinus P cf. nanus P. cf. ephebeus P. cf. ephebeus P. cf. ephebeus P. cf. ephebeus P. cf. ephebeus P cf. fastigiatus P cf. fuliginosus P. chrysophlebius P. chrysophlebius P. chrysophlebius P. chrysophlebius P. chrysophlebius P. chrysophlebius P cutefractus P cutefractus P cutefractus P. cystidiosus P. cystidiosus P. cystidiosus P cystidiosus P. cystidiosus P. cystidiosus P. diptychocystis P. ephebeus P. fenzlii P fenzlii P. fenzlii P fulvibadius P. fulvibadius P gausapatus P gausapatus Collection iNaturalist 112240775 MO 136488 BPI 882530 BPI 882531 HHB1213 AJ478 AJ535 HMJAU 60207 HMJAU 60208 GDGM41547 VES1231-5 AJ 857 AJ 860 HMJAU 60206 HMJAU 60210 REG 13641 LE 213093 LOU15198 Shaffer4673 Pearson sn 9823 10151 NKI12 FK2158 TNSF12383 SF10 (BPI) TNSF12388 SF12 (BPI) SF11 (SIU) FJAU66561 BRNM825872 GM 3458 FG 26092015 LE 312852 LE 33355 AJ 782 (NBM-F-009790) AJ 617 (NBM-F-009788) FJAU66556 FJAU66557 NMJ184 AJ234 TNSF12376 F1020647 LE 246083 AJ 815 HRL3391 BRNM817745 BRNM817745 Country USA (TN) USA (TN) USA-IIlinois USA-IIlinois USA-New Mexico USA-Vigin Islands Dominican Republic China China China Russia (Europe) USA, Arkansas USA, Arkansas China China USA Russia Spain France England Italy Italy Brazil Brazil Japan USA (IL) Japan USA (IL) USA (IL) China Spain Spain Slovenia Russia (Far East) Russia (Far East) USA (MA) USA (NY) China China Brazil Spain Japan Slovakia Russia USA, California Canada, Québec South Korea South Korea MycoKeys 104: 91-112 (2024), DOI: 10.3897/mycokeys.104.117841 GenBank No. ITS TEF1-a OR229047 OR242143 KM983689 OR242144 JQ065025 = JQ065026 7 KM983670 = KM983675 = KM983676 = 0OM991943 OP573273 OM992247 OP573274 MK791275 = ON864103 ON813296 KM983701 ON813290 KM983699 ON813288 OM991893 > OM943513 oa HM562152 = FJ774081 = KM983671 5 HM562080 7 HM562198 = JF908620 = JF908621 - KM983678 7 KM983677 ad HM562125 = HM562180 = HM562088 a HM562182 = HM562181 = OR994065 PP062824 OR229050 OR242162 OR229048 OR242165 OR229053 OR242164 OR229063 OR242175 OR229062 OR242174 KM983687 OR242171 KM983686 OR242173 OR994068 PP062825 PP002166 PP062826 KM983674 = HM562044 = HM562091 = HM562111 am FJ774082 a KM983698 ON813285 ON864094 ON813287 OR229067 OR242177 OR229067 OR242177 Reference Sevcikova et al. 2023 Sevcikova et al. 2023 Menolli et al. 2015 Menolli et al. 2015 Menolli et al. 2015 Menolli et al. 2015 Menolli et al. 2015 Qi et al. 2022 Qi et al. 2022 Sevcikova et al. 2022 Sevcikova et al. 2022 Sevcikova et al. 2022 Sevcikova et al. 2022 Qi et al. 2022 Qi et al. 2022 Qi et al. 2022 Justo et al. 2011 Menolli et al. 2015 Menolli et al. 2015 Menolli et al. 2015 Menolli et al. 2015 Menolli et al. 2015 Menolli et al. 2015 Menolli et al. 2015 Justo et al. 2011a Justo et al. 2011a Justo et al. 2011a Justo et al. 2011a Justo et al. 2011a This study Sevcikova et al. 2023 Sevcikova et al. 2023 Sevcikova et al. 2023 Sevcikova et al. 2023 Sevcikova et al. 2023 Sevcikova et al. 2023 Sevcikova et al. 2023 This study This study Menolli et al. 2015 Menolli et al. 2015 Menolli et al. 2015 Menolli et al. 2015 Holec et al. 2017 Sevcikova et al. 2022 Sevcikova et al. 2022 Sevcikova et al. 2023 Sevcikova et al. 2023 94 Zheng-Xiang Qi et al.: New species, newly recorded and common species of Pluteus sect. Celluloderma Taxon P halonatus P. halonatus P heteromarginatus P hirtellus P inconspicuus P inflatus P inflatus P inflatus P insidiosus P longistriatus P lucidus P mammillatus P. mammillatus P mammillatus P brunneodiscus P brunneodiscus P brunneodiscus P. parvisporus P. parvisporus P. phlebophorus P. phlebophorus P. phlebophorus P. phlebophorus P plautus P. podospileus P. podospileus P. podospileus P riberaltensis var. conquistensis P romellii P. romellii P romellii P romellii P romellii P romellii P rugosidiscus P rugosidiscus Pluteus sp. Pluteus sp. P. squarrosus P. squarrosus P. thomsonii P. tomentosulus P. tomentosulus V. michiganensis Volvopluteus michiganensis Collection FK2084 NKI17 AJ172 SFSU:DED 8259 PDD 72485 BRNM817761 BRNM825836 BRNM825837 15120 Minnis309203 LE F-347426 Singer244A Minnis309202 ASM7916 FJAU66132 FJAU66133 FJAU66134 AJ 855 iNaturalist 112236342 AJ 81(NBM-F-009110) AJ228 (LOU) AJ194 (LOU) AJ193 (LOU) P59 LE 303682 LE 303687 LE 313589 FK1043 AJ 232 BRNM 761731 BRNM 816205 BRNM 825845 FJAU66558 FJAU66559 BRNM/761706 Homola109 (MICH) SP394389 iNaturalist 27406926 (NBM-F-009806) GDGM 42320 GDGM 42302 LE 303662 M0163564 MO093719 HMJAU-CR45 HMJAU-CR43 Country Brazil Brazil USA West Africa New Zealand Czech Republic Czech Republic Czech Republic Italy USA Russia USA-Florida USA-Missouri USA-Missouri China China China USA, Arkansas USA, Tennessee Spain Spain Spain Spain USA-California Russia (South Siberia) Russia (South Siberia) Russia (South Siberia) Brazil Spain Czech Republic Czech Republic Slovakia China China Slovakia USA (MI) USA USA (IN) China China Russia USA-Pennsylvania USA-Oregon China China Bold fonts are the sequences to be determined in this study. MycoKeys 104: 91-112 (2024), DOI: 10.3897/mycokeys.104.117841 GenBank No. ITS TEF1-a KM983680 = KM983679 = HM562058 a MG968804 = MN738614 = OR229033 OR242136 OR229035 OR242132 OR229036 OR242133 JF908626 = HM562082 7 0Q732746 = HM562120 . HM562086 = HM562119 = PP002168 PP062821 PP002169 PP062822 PP002167 PP062823 ON864099 ON813295 ON864098 ON813294 HM562039 ON133554 HM562138 aa HM562137 = HM562144 = KF306016 = KX216331 OR242169 KX216332 OR242168 OR229060 OR242167 HM562162 = HM562062 ON813280 ON864065 ON813278 ON864063 ON813276 ON864070 ON813281 OR994057 PP062827 OR994061 PP062828 MH010876 LT991752 HM562079 = HM562161 — ON006984 OR242176 MK791274 = MK791273 = KX216329 = KM983673 5 KM983672 = MW242665 = MW242664 = Reference Menolli et al. 2015 Menolli et al. 2015 Hosen et al.2019 Desjardin and Perry 2018 Sevcikova et al. 2023 Sevcikova et al. 2023 Sevcikova et al. 2023 Sevcikova et al. 2023 Justo et al. 2012 Hosen et al.2019 Malysheva et al. 2023 Holec et al. 2017 Holec et al. 2017 Holec et al. 2017 This study This study This study Sevcikova et al. 2022 Sevcikova et al. 2022 Sevcikova et al. 2023 Justo et al. 2011a Justo et al. 2011a Justo et al. 2011a Menolli et al. 2015 Sevcikova et al. 2023 Sevcikova et al. 2023 Sevcikova et al. 2023 Menolli et al. 2015 Sevcikova et al. 2022 Sevcikova et al. 2022 Sevcikova et al. 2022 Sevcikova et al. 2022 This study This study Sevcikova et al. 2023 Justo et al. 2011a Justo et al. 2012 Sevcikova et al. 2023 Hosen et al.2019 Hosen et al.2019 Justo et al. 2012 Menolli et al. 2015 Menolli et al. 2015 Qi et al. 2022 Qi et al. 2022 95 Zheng-Xiang Qi et al.: New species, newly recorded and common species of Pluteus sect. Celluloderma Malysheva et al. 2023; Sevcikova et al. 2023; Xu et al. 2023), and details of the ITS and TEF1-a sequences of these species are shown in Table 1. The ITS and TEF1-a dataset comprised 134 representative sequences that exhibited the highest similarity to Pluteus spp., and two sequences of Volvopluteus mich- iganensis (A.H. Sm.) Justo and Minnis. as an outgroup. For obtaining ITS + TEF1-a datasets of related species, sequence alignment was initially performed for ITS and TEF1-a using the “automatic” strategy and normal alignment mode of MACSE V2.03 (Ranwez et al. 2018) and MAFFT (Katoh and Standley 2013), respectively. Subsequently, the alignments were manually adjusted in BioEdit v7.1.3 (Hall 1999). Afterward, ITS and TEF1-a sequences were aligned and combined using Phylosuit V1.2.2 (Zhang et al. 2020). Then, ModelFinder (Kalyaanamoorthy et al. 2017) was used to select the best-fit models using the Bayesian information criterion (BIC). In this case, the Maximum likelihood (ML) analyses were performed in IQTree 1.6.8 (Nguyen et al. 2015), and the Bayesian inference phylogenies were performed in MrBayes 3.2.6 (Ronquist et al. 2012) (two parallel runs, 2,000,000 generations), in which the initial 25% of sampled data were discarded as burn-in. The above software was integrated into PhyloSuite 1.2.2 (Zhang et al. 2020). The ML phylogenetic tree was evaluated using the bootstrap method with a bootstrap value of 1,000 replicates; BI determined that the analysis reached smoothness with a variance of less than 0.01 and terminated the calculation. Finally, the evolutionary tree was followed up with Figtree v1.4. Results Phylogenetic analyses This study's nrlTS dataset comprises 93 sequences and 650 characters (gaps included). The TEF1-a dataset comprises 41 sequences and 530 characters (gaps included). The combined nrlTS + TEF1-a dataset consists of 134 se- quences and 1180 characters, including gaps. Of these, 16 sequences (8 nrITS and 8 TEF1-a) were newly generated in this study (Table 1). The overall topolo- gies of the ML and BI trees were nearly identical for all datasets. For clarity and brevity, we use the term “strongly supported” for a clade/rela- tion that receives a bootstrap (BS) 90 and a posterior probability (PP) = 1, and “well supported” if it receives a BS 70 and a PP of 0.95. The individual support values are shown in Fig. 1. Within the sect. Celluloderma, six strongly supported clades are recovered in the combined nrlTS + TEF1-a dataset: i. Clade I: This includes the clade we consider to represent P mammillatus (Longyear) Minnis, Sundb. & Methven from the USA, P. fenzlii (Schulzer) Cor- riol & P-A. Moreau from Japan, Slovakia, and Russia, P. halonatus from Brazil. . Clade Il: Includes only the newly described P. brunneodiscus from China. This also includes the clade we consider to represent P squarrosus Hosen & T.H. Li from China, P. hirtellus Desjardin & B.A. Perry from West Africa, P. plautus (Weinm.) Gillet from the USA, P tomentosulus Peck from the USA, P. diptychocystis Singer from Brazil, and P riberaltensis var. conquis- tensis from Brazil, while P ephebeus from Spain, France, England, and Italy MycoKeys 104: 91-112 (2024), DOI: 10.3897/mycokeys.104.117841 96 Zheng-Xiang Qi et al.: New species, newly recorded and common species of Pluteus sect. Celluloderma nrITS + TEF1-a dataset Clade I 100/1 Clade III 99/0.99 82/0.83 100/1 = 100/1 , HMJAU CR45 Volvopluteus michiganensis HMJAU CR43 Volvopluteus michiganensis 0.08 99/0.99) 95/0.9 > 602011 Pluteus brunneidiscus 100/1! HMJAU 60206 Pluteus brunneidiscus 100/1 = AJ172 Pluteus heteromarginatus Minnis309203 Pluteus longistriatus 93/0.8] | AJ535 Pluteus aff. ephebeus mae NKI12 Pluteus cf. fastigiatus 99/ll_PK2158 Pluteus cf. fuliginosus 99/1 ASM7916 Pluteus mammillatus | 100/1 100/1 Minnis309202 Pluteus mammillatus Singer244A Pluteus mammillatus 99/0.84 F1020647 Pluteus fenzlii ie? ut LE 246083 Pluteus fenzlii 97/0.98_ TNSF12376 Pluteus fenzlii 100/1; FK2084 Pluteus halonatus | NKI17 Pluteus halonatus i GDGM 42302 Pluteus squarrosus GDGM 42320 Pluteus squarrosus | SFSU DED 8259 Pluteus hirtellus 043 Pluteus riberaltensis var. conquistensis NMJ184 Pluteus diptychocystis AJ234 Pluteus ephebeus ; BPI 882530 Pluteus aff. ephebeus 99/1! BPI 882531 Pluteus aff. ephebeus Shaffer4673 Pluteus cf. ephebeus Pearson sn Pluteus cf. ephebeus LOU15198 Pluteus cf. ephebeus FJAU66132 Pluteus brunneodiscus 95/0.82 opejo 11zu97 99/1 100/1 FJAU66133 Pluteus brunneodiscus 8) FJAU66134 Pluteus brunneodiscus HHB1213 Pluteus aff. ephebeus M093719 Pluteus tomentosulus i 100/1! MO163564 Pluteus tomentosulus JF908620 Pluteus cf. ephebeus JF908621 Pluteus cf. ephebeus KF306016 Pluteus plautus AJ617 Pluteus cystidiosus opelo snoqoydq 100/1 99/0.95 70/0.67 86/08: AJ782 Pluteus cystidiosus 01) FJAU66556 Pluteus cystidiosus 1oo/t| | LE F 312852 Pluteus cystidiosus LE F 313335 Pluteus cystidiosus 1 ot LE 303687 Pluteus podospileus LE F 313589 Pluteus podospileus PDD 72485 Pluteus inconspicuus BRNM817745 Pluteus gausapatus 100/1 9710.91) 100 BRNM825836 Pluteus inflatus BRNM825837 Pluteus inflatus [ FJAU66556 Pluteus cystidiosus LE 303682 Pluteus podospileus | _ jNaturalist 27406926 Pluteus sp. BRNM817761 Piluteus inflatus | apryo snoyidsopog MO136488 Pluteus absconditus iNaturalist 112240775 Pluteus absconditus BRNM825872 Pluteus cutefractus t FG26092015 Pluteus cutefractus | | GM3458 Pluteus cutefractus LEF 347426 Pluteus lucidus 99/0.99 ¢ Ad 232 Pluteus romellii 99/0.98 FJAU66559 Pluteus romellii “| BRNM 761731 Pluteus romellii 100/1} BRNM 816205 Pluteus romellii BRNM 825845 Pluteus romellii FJAU66558 Pluteus romellii AJ 815 Pluteus fulvobadius [ =L HRL3391 Pluteus fulvobadius AJ 857 Pluteus austrofulvus al AJ 860 Pluteus austrofulvus AJ 855 Phiteus parvisporus iNaturalist 112236342 Pluteus parvisporus | , GDGM41547 Pluteus aurantiorugosus j 99/0.97 Ope]o II]JOWIOY Clade IV - SP394389 Pluteus sp. AJ193 Pluteus phlebophorus 100/ AJ194 Pluteus phlebophorus AJ228 Pluteus phlebophorus AJ81 Pluteus phlebophorus TNSF12394 Pluteus phlebophorus '__ LE 213093 Pluteus cf. nanus 100/1 100/1-—-BRNM 761706 Phiteus rugosidiscus { Homolal09 Pluteus rugosidiscus FJAU66561 Pluteus chrysophlebius | [_ TNSF12388 Pluteus chrysophlebius | TNSF12383 Pluteus chrysophlebius SF10 Pluteus chrysophlebius SF11 Pluteus chrysophlebius | SF12 Pluteus chrysophlebius 15120 Pluteus insidiosus i___"_ LE 303662 Pluteus thomsonii REG 13641 Pluteus cervinus | Sect. Pluteus oped sniqgoyydosArys Clade VI 100/1 | Thomsonii clade | Sect. Hispidoderma | Outgroup DULAAPOINI) °DIS Figure 1. Phylogenetic tree of the sect. Celluloderma of the genus Pluteus. The best tree from the ML and BI analysis of the nrlTS + TEF1-a dataset. The two values of internal nodes respectively represent the maximum likelihood bootstrap (MLBP)/Bayesian posterior probability (BIPP). This study species is in bold and red font. MycoKeys 104: 91-112 (2024), DOI: 10.3897/mycokeys.104.117841 97 Zheng-Xiang Qi et al.: New species, newly recorded and common species of Pluteus sect. Celluloderma (P cf. ephebeus and P. aff. ephebeus), P. fuliginosus Murrill from Brazil (P. cf. fuliginosus), P. fastigiatus Singer from Brazil (P. cf. fastigiatus). iii. Clade III: Includes the newly described P. cystidiosus (China). This clade also includes the clade we consider to represent P podospileus Sacc. & Cub. (Russia), P cutefractus Ferisin, Dovana & Justo (Spain, Slovenia), P inflatus Velen (Czech Republic), P inconspicuus E. Horak (New Zealand); three recently described species, P cystidiosus (Russia, USA), P abscondi- tus Justo, Kalichman & S.D. Russell (USA), and P. gausapatus Sevéikova & Antonin (South Korea), and one likely undescribed species from the USA (iNaturalist 27406926). iv. Clade IV: Includes the newly described P. romellii (China). It also includes P. fulvibadius Murrill (USA and Canada), P aurantiorugosus (Trog) Sacc (China and Russia). Three recently described species, P austrofulvus Jus- to, Minnis, S.D. Russell & Kalichman (USA), P. parvisporus Justo, Kalichman & S.D. Russell (USA) and P aletaiensis Z.X. Qi, B. Zhang and Yu Li (China). v. Clade V: Includes the newly described P. chrysophlebius (China). This clade also includes the clade we consider to represent P. chrysophlebius (Japan, USA, Japan), P. phlebophorus (Ditmar) PR. Kumm (Spain), and P. ru- gosidiscus Murrill (Slovakia, USA). Clade VI: This clade includes the clade that we consider to represent P. in- sidiosus Vellinga & Schreurs (Italy) and P. thomsonii (Berk. & Broome) Den- nis (Russia). Vi. Taxonomy Pluteus brunneodiscus Z.X. Ql, B. Zhang & Y. Li, sp. nov. MycoBank No: 851479 Figs 2A-B, 3 Typification. CHINA. Xinjiang Uygur Autonomous Region, Ili Kazakh Autono- mous Prefecture, Tekes County, Aktamu Wetland, 43°15'22.61"N, 81°75'90.21'"E, alt. 1243 m, 6 July 2022, Z.X. Qi (FJAU 66134, holotype!). Sequences holotype. ITS: PP002167, TEF1-a: PP062823. Etymology. “brunneo-”: brown, “-discus”: pileus disc. The species epithet “brunneodiscus” (Lat.) refers to the brown of the middle part of the pileus disc. Diagnosis. Pluteus brunneodiscus differs from P. tomentosulus by its brown pileus in the middle, transitioning to white toward the margins, and the surface cracks to form irregular granules. It grows in poplar forests (Populus alba var. pyramidalis Bge) with decaying wood branches or chips. Description. Basidiomata medium to large. Pileus 39-71 mm in diam, initially compressed hemispherical, surface with dense brown irregular granules (5.0YR 5/2), dirty white (5.0YR 9/2), middle brown (5.0YR 4/4), margin entire, gradually spreading at maturity, pileus middle dark brown (5.0YR 3/6), margin irregularly dehiscent at maturity or after hygrophanous. Context whitish (5.0YR 9/2), odor- less, 3-6 mm thick. Lamellae initially dirty white (5.0YR 9/2), becoming flesh- brown to earth-brown at maturity (5.0YR 8/4- 5.0YR 6/4), free, dense, thick, un- equal, slightly ventricose, 6-7 mm wide. Stipe 37-55 mm long, 8-11 mm wide, dirty white (5.0YR 9/2), cylindrical, slightly thicker at the base, fibrous, with white longitudinal stripes on the surface. Odorless. Spore prints pink. MycoKeys 104: 91-112 (2024), DOI: 10.3897/mycokeys.104.117841 98 Zheng-Xiang Qi et al.: New species, newly recorded and common species of Pluteus sect. Celluloderma Ae Figure 2. Basidiomata features A-B Pluteus brunneodiscus C-D P cystidiosus E-F P. chrysophlebius G-I P. romellii. Pho- tos by Zheng-xiang Qi (A-B, G-I). Photos by Di-zhe Guo (C-F). Scale bars: 1 cm. MycoKeys 104: 91-112 (2024), DOI: 10.3897/mycokeys.104.117841 Zheng-Xiang Qi et al.: New species, newly recorded and common species of Pluteus sect. Celluloderma Basidiospores [120, 12, 3] (-6.5) 7.0-7.5 (-8.0) x 5.0-6.0 (-6.5) um, avL x avW = 7.0 x 6.0 um, Q = 1.16-1.30-1.45 um, avQ = 1.16 um, globose, subglobose, slightly pink, smooth, thin-walled, non-dextrinoid, partially contain- ing one droplet or irregular inclusions. Basidia 25-32 x 7-11 um, fusiform to clavate, thin-walled, 4—sterigmate, and hyaline in KOH. Pleurocystidia abun- dant, scattered, 55-102 x 22-36 um, vesicular to narrowly vesicular, or clavate, thin-walled, smooth, and hyaline in KOH. Cheilocystidia abundant, clustered, 41-79 x 18-29 um, subfusiform to fusiform, or ventrally bulbous, apically broadly digitate 15-23 um long, thin-walled, hyaline. Lamellar trama divergent. Pileipellis a cutis to trichodermium, hyphae 4-10 um diam, cylindrical, hyaline, non-gelatinous; terminal cells inflated, 62-91 x 22-31 um, obtusely rounded or pointed apically, thin-walled, with brown cytoplasmic pigments. Stipitipellis a cutis, hyphae 5-9 um diam, cylindrical, hyaline, non-incrusted, non-gelatinous, thin-walled. Caulocystidia absent. Clamp connections absent in all tissues. Ecology and distribution. Solitary to scattered on the ground in the broad- leaved forests (Populus alba var. pyramidalis Bge) with decaying wood branch- es or wood chips. Known from Xinjiang Uygur Autonomous Region of China. Additional specimens examined. CHINA. Xinjiang Uygur Autonomous Re- gion, Illi Kazakh Autonomous Prefecture, Tekes County, Aktamu Wetland, 43°15'22.61"N, 81°75'90.21"E, alt. 1243 m, 6 July 2022, Z.X. Qi, D.M. Wu, N. Gao and B.K. Cui, FJAU 66132 (ITS: PP002168, TEF1-a: PP062821). CHINA. Xinjiang Uygur Autonomous Region, Ili Kazakh Autonomous Prefecture, Tekes County, Aktamu Wetland, 43°15'22.61"N, 81°75'90.21"E, alt. 1243 m, 6 July 2022, Z.X. Qi, FJAU 66133 (ITS: PP002169, TEF1-a: PP062822). Notes. Morphologically, Pluteus brunneodiscus is very similar to P tomentosu- lus in having a white pileus. The difference lies in the surface texture, as P tomento- sulus has a very finely granular-tomentose surface that becomes bald at maturity, while P brunneodiscus features a brown center of the pileus, transitioning to white toward the margins, with the surface cracking to form irregular granules (Vellinga and Schreurs 1985; Orton 1986; Vellinga 1990; Desjardin and Perry 2018). In phylogenetic analyses, P brunneodiscus clusters in the ephebeus clade as a sister species to P. aff. ephebeus, and has a support ratio of 1/100. How- ever, the pileus of P aff. ephebeus are sooty, shield-shaped fruiting bodies with pubescent or downy surfaces. They grow on rotting wood or stumps and are widely distributed in Britain and Ireland (Orton 1986; Justo et al. 2011a; Menolli et al. 2015). These characteristics distinguish P brunneodiscus from P aff. ephebeus. Pluteus cystidiosus (Minnis and Sundb.) Justo, Malysheva & Lebeuf, in Sevéikova et al., Journal of Fungi 9(9, no. 898): 34 (2023) Figs 2C-D, 4 Pluteus seticeps var. cystidiosus Minnis and Sundberg N. Amer. Fung. 5(1): 13 (2010). Syn. Description. Basidiomata medium to large. Pileus 25-41 mm in diam, com- pressed hemispherical, surface spreading when young, surface with longitu- dinal vein-like folds from middle to margin when mature, margin mostly trans- MycoKeys 104: 91-112 (2024), DOI: 10.3897/mycokeys.104.117841 100 Zheng-Xiang Qi et al.: New species, newly recorded and common species of Pluteus sect. Celluloderma i Figure 3. A Macroscopic characteristics of Pluteus brunneodiscus B basidiospores C pleurocystidia D basidia E pileipellis terminal cells F cheilocystidia. Scale bars: 1 cm (A); 10 um (B-F). verse folds, light brown to dark brown (5.0YR 5/6-5.0YR 4/12), margin entire. Context dirty white (2.5YR 9/4), odorless, 5-8 mm thick. Lamellae dirty white (2.5YR 9/4), free, dense, thick, unequal, ventricose, 15-18 mm wide. Stipe 30- 41 mm long, 12-17 mm wide, cylindrical, slightly thicker at the base, hollow, MycoKeys 104: 91-112 (2024), DOI: 10.3897/mycokeys.104.117841 101 Zheng-Xiang Qi et al.: New species, newly recorded and common species of Pluteus sect. Celluloderma a Figure 4. A Macroscopic characteristics of Pluteus cystidiosus B caulocystidia C basidiospores D pleurocystidia E chei- locystidia F basidia G pileipellis. Scale bars: 1 cm (A); 10 um (B-G). MycoKeys 104; 91-112 (2024), DOI: 10.3897/mycokeys.104.117841 102 Zheng-Xiang Qi et al.: New species, newly recorded and common species of Pluteus sect. Celluloderma fibrous, with brown serpentine or crumbly scales on the surface (2.5YR 9/2). Odorless. Spore prints pink. Basidiospores [200, 10, 2] (—5.0) 5.5-6.0 (—6.5) x (—4.5) 5.0-5.5 um, avL x avW = 6.0 x 5.0 um, Q = 1.10-1.20-1.30 pm, avQ = 1.20 um, spherical, subglo- bose, slightly pink, smooth, thin-walled, non-dextrinoid, partially containing one droplet or irregular inclusions. Basidia 23-31 x 7-10 um, clavate, thin-walled, 4-sterigmate, and hyaline in KOH. Pleurocystidia abundant, scattered, 55-102 x 22-36 um, rod-shaped or subpyriform, vesicular, thin-walled, smooth, and hy- aline in KOH. Cheilocystidia abundant, clustered, 37-60 x 15-22 um, clavate, fusiform or vesicular, thin-walled. Lamellar trama divergent. Pileipellis a hymeni- derm or epithelioid hymeniderm, made up of two types of elements; spherope- dunculate or pyriform, 27-55 x 24-34 um; broadly fusiform, inflated-fusiform, lanceolate, narrowly utriform, often mucronate, 56-105 x 11-23 um; all ele- ments with brown intracellular pigment, often aggregated in spots, slightly thick-walled. Stipitipellis a cutis of cylindrical, hyphae 8-11 um wide, with pale brown pigment. Caulocystidia common, often in clusters, 36-112 x 9-20 um, cylindrical, narrowly clavate, narrowly fusiform, spheropedunculate, with brown or yellow-brown pigment. Clamp connections absent in all studied tissues. Ecology. Scattered on decaying wood in mixed coniferous forests (Pinus ko- raiensis Siebold and Zucc). Distribution. Canada, the USA, Japan, Russian Far East. Additional specimens examined. CHINA. Heilongjiang Province, Liangshui National Nature Reserve. 47°11'22.24"N, 128°47'89.11"E, 23 June 2019, D.2Z. Guo, FJAU 66556 (ITS: OR994068, TEF1-a: PP062825). CHINA. Heilongjiang Province, Liangshui National Nature Reserve. 47°11'22.24"N, 128°47'89.11'E, 28 June 2019, D.Z. Guo, FJAU 66557 (ITS: PP002166, TEF1-a: PP062826). Note. Sevcikova et al. (2023) elevated Pluteus seticeps var. cystidiosus to P cystidiosus based on specimens from the USA, Canada, Japan, and Russia. The present study reports P. cystidiosus as a new record in China. There was almost complete overlap in morphological variation between those report- ed in the present study and the holotype specimen. Both grow in temperate/ cold-temperate forests. However, the basidiospores of the species in the pres- ent study were slightly larger, measuring (-—5.0) 5.5-6.0 (-—6.5) x (-4.5) 5.0- 5.5 um, while those of the holotype specimen were smaller, measuring 4.5-5.5 (-6.2) x 3.5-5.0 um. The phylogenetic tree also supports the results of our morphological study, showing that our specimens are clustered in the same branch as those from the USA and Russia, with a support ratio of 1/100. Pluteus chrysophlebius (Berk. & M.A. Curtis) Sacc., Syll. fung. (Abellini) 5: 678 (1887) FIGS ZE—F-5 Agaricus chrysophlebius Berk. and M.A. Curtis 1859. Syn. Description. Basidiomata medium. Pileus 15-22 mm in diameter, surface not spreading, irregularly pitted, smooth, central part umbo, wrinkled or veined, yel- low to bright yellow (5.0Y 9/12-5.0Y 9/20), with a hyaline stripe in the central MycoKeys 104: 91-112 (2024), DOI: 10.3897/mycokeys.104.117841 103 Zheng-Xiang Qi et al.: New species, newly recorded and common species of Pluteus sect. Celluloderma ‘QUIRES Figure 5. A macroscopic characteristics of Pluteus chrysophlebius B basidiospores C basidia D pleurocystidia E cheilo- cystidia F pileipellis. Scale bars: 1 cm (A); 10 um (B-G). MycoKeys 104; 91-112 (2024), DOI: 10.3897/mycokeys.104.117841 104 Zheng-Xiang Qi et al.: New species, newly recorded and common species of Pluteus sect. Celluloderma part 3/4 of the way toward the margin, margin entire. Context yellowish (5.0Y 9/8), odor inconspicuous. Lamellae yellow to brownish yellow (5.0Y 9/6- 5.0Y 9/8), free, dense, thick, unequal, ventricose, 6-8 mm wide. Stipe 25-42 mm long, 4-6 mm wide, cylindrical, slightly thicker at the base, fibrous, bright yellow to yellow (5.0Y 9/10-5.0Y 9/18), smooth, with white tomentose dense cilia at the base. Odorless. Spore prints pink. Basidiospores [90, 3, 1] 5.5-6.0 x (-4.5) 5.0-5.5 um, avL x avW = 6.0 x 5.0 um, Q = 1.09-1.20-1.33 um, avQ = 1.20 um, globose, subglobose, slightly pinkish, smooth, thinly walled, non-dextrinoid, partially containing one droplet or irregular inclusions. Basidia 23-34 x 7-11 um, clavate, thin-walled, 4-sterig- mate, and hyaline in KOH. Pleurocystidia scattered, 52-78 x 15-24 um, broad and long-necked vase-like, partly with a long neck, neck with inclusions, thin- walled, smooth, and hyaline in KOH. Chilocystidia abundant, clustered, smaller, 45-66 x 14-21 um, similar to pleurocystidia, long-necked vase-shaped to fu- siform, thin-walled. Lamellar trama divergent. Pileipellis an euhymeniderm of spheropedunculate and subglobose elements 28-67 x 18-41 um, with brown or light brown, at the center brown to dark brown. Stipitipellis a cutis, hyphae 5-9 um wide, hyaline, non-gelatinous, thin-walled. Caulocystidia absent. Clamp connections absent in all tissues. Ecology. Solitary on decaying wood in mixed coniferous forests. Distribution. North America, South America. Additional specimens examined. CHINA. Heilongjiang Province, Liangshui National Nature Reserve. 47°11'22.24"N, 128°47'89.11"E, 24 June 2019, D.Z. Guo, FJAU 66561 (ITS: OR994065, TEF1-a: PP062824). Note. Pluteus chrysophlebius was first reported in China. It can be distin- guished from other yellow-pileus species such as P. admirabilis (Peck) Peck, P aurantiacus Murrill, RP melleus Murrill, and P rugosidiscus Murrill by its yel- lowish pileus and stipe, as well as its bald pileus texture (Minnis and Sundberg 2010; Malysheva et al. 2016). The phylogenetic analysis also supports the dif- ferentiation of species. In the phylogenetic tree, P chrysophlebius formed a cluster with TNSF12383 and TNSF12388 in Asia and was sister to SF10-SF12 in the United States, with strong support for both clades. Pluteus romellii (Britzelm.) Lapl., Dict. iconogr. champ. sup. (Paris): 533 (1894) Figs 2G-l, 6 Agaricus romellii Britzelm., Hymenomyceten aus Siidbayern VIII: 5 (1891). Syn. Description. Basidiomata medium to large. Pileus 20-56 mm broad, com- pressed hemispherical to spreading, surface with vein-like projections extend- ing to the pileus margin, often with striated dehiscence, with a greasy or almost waxy texture, brown to yellowish-brown (7.5YR 8/8-7.5YR 6/12), margins wavy dehiscence with translucent-striate. Context light yellow (7.5YR 8/12), odor- less, 2-3 mm thick. Lamellae yellowish (10.0YR 8/10), free, medium dense, unequal, entire, ventricose, 5-7 mm wide. Stipe 26-41 mm long and 4-8 mm wide, cylindrical, slightly thicker at the base, fibrous, upper part of the stipe white to yellowish (10.0YR 9/8-10.0YR 7/12), smooth, lower part of the stipe MycoKeys 104: 91-112 (2024), DOI: 10.3897/mycokeys.104.117841 105 Zheng-Xiang Qi et al.: New species, newly recorded and common species of Pluteus sect. Celluloderma Figure 6. A macroscopic characteristics of Pluteus romellii B basidiospores C pleurocystidia D basidia E cheilocystidia F pileipellis. Scale bars: 1 cm (A); 10 um (B-E); 20 um (F). MycoKeys 104; 91-112 (2024), DOI: 10.3897/mycokeys.104.117841 106 Zheng-Xiang Qi et al.: New species, newly recorded and common species of Pluteus sect. Celluloderma with white tomentum, yellow to yellow-brown (10.0YR 8/8-10.0YR 8/12). Odor- less. Spore print pale pink. Basidiospores [120, 4, 2] 7.0-7.5 (-8.0) x 6.0-6.5 um, avL x avW = 7.0 x 6.0 um, Q = 1.07-1.25~1.33 um, avQ = 1.16 um, globose, subglobose to el- lipsoid, transparent to slightly pinkish, smooth, and thin-walled, non-dextri- noid, partially containing one droplet or irregular inclusions. Basidia 27-32 x 8-10 um, clavate, thin-walled, 4-sterigmate, and hyaline in KOH. Pleurocystidia abundant, scattered, 55-102 x 22-36 um, rod-shaped or subcylindrical, fusi- form, with neck and apical part broader and obtuse, thinly walled, smooth, and hyaline in KOH. Cheliocystidia abundant, clustered, 41-79 x 18-29 um, pyri- form or similarly pleurocystidia shape, thin-walled. Lamellar trama divergent. Pileipellis an euhymeniderm of spheropedunculate and subglobose elements 25-48 x 23-35 um, with brown or light brown, at the center brown to dark brown. Stipitipellis a cutis, hyphae 6-10 um wide, hyaline, non-gelatinous, thin- walled. Caulocystidia absent. Clamp connections absent in all tissues. Ecology. Solitary to scattered on decaying wood in coniferous forests (Picea schrenkiana Fisch.). Distribution. Europe, Americas, East Asia, Africa. Additional specimens examined. CHINA. Xinjiang Uygur Autonomous Re- gion, Ili Kazakh Autonomous Prefecture, Tekes County, Jongkushtai Village, 43°12'26.61'"N, 81°91'97.21"E, alt. 2139 m, 10 July 2022, Z.X. Qi, J.J. Hu, and B. Zhang, FJAU 66558 (ITS: OR994057, TEF1-a: PP062827). CHINA. Xinjiang Uygur Autonomous Region, Ili Kazakh Autonomous Prefecture, Tekes County, Jongkushtai Village, 43°15'22.61"N, 81°75'90.21"E, alt. 2147 m, 11 July 2022, Z.X. Qi, J.J. Hu, and B. Zhang, FJAU 66559 (ITS: OR994061, TEF1-a: PP062828). Note. Initially, the description of Pluteus romellii was rather vague (Britzel- mayr 1891), stating that P romellii was similar to P nanus (Pers.) P. Kumm, with spores measuring 6-7 um, and found growing in the soil of Bavaria. It is now widely acknowledged that P. romellii is characterized by a brown pileus, yellow stipe, and the absence of elongated elements in the pileipellis. This species is placed on the phylogenetic tree in subsect. Eucellulodermini under sect. Cellulo- derma (Orton 1986; Vellinga 1990; Sevcikova et al. 2023). Here, our description of the P romellii is consistent with the commonly accepted characterization. Phylogenetic analysis shows that it clustered with the epitype (BRNM 761731) with strongly supported (99/0.98). Key to the reported species of Pluteus sect. Celluloderma in China 1 Pileipellis consists of spheropedunculate cells and elongated cystidioid GIGI ES se. 27. Shen ocak ee oe Marre eter gcc ess bee sean eee ck susie ee spe eoc rol cesh ween 2 - Pileipellis consists of spoheropedunculate cells without elongated cystidi- GIG ClONMNGINTS iF ett ue O ahele enn tcl AY Non Ae ED oe 7 De BPA CAMIDCYS HON cecieuwactemes Peddceetir nie Bens ee Pnnancact an aedtesan suede an nleereuie en 3 = SE WVIthOUPCAUIDCYSHClat =. els scm ws se os ee, ee ee 6 Ste With) DISUEOCY SUG lake. «25.5008, 2.5 seer tena teat pattern hangs a Mood emer viene escent 4 Tt VEIT ROUT PROUNOCYSTGI AS 1.8 220: eocredas Prez cbornbdduor’ senne, Pluteus cinnabarinus 4 _Cheilocystidia with short to long mucronate at the apex ................cccceeeeee Mtcana pene Maoicst AB ceeti ieee sah tnanrebii Sash tt naarat ad Re Macnee hitie Pluteus aurantioruber - Cheilocystidia without short to long mucronate at the apex...................6. 5 MycoKeys 104: 91-112 (2024), DOI: 10.3897/mycokeys.104.117841 107 Zheng-Xiang Qi et al.: New species, newly recorded and common species of Pluteus sect. Celluloderma 5 Pleurocystidia larger, measuring 35-73 (—82) x 11-31 UM... eee Oa oP nes A ae a nse Se MD Org ROP SP | RARER, PEE tal Pluteus cystidiosus - Pleurocystidia smaller, measuring 36-51 x 13.4-24 UM... eee ceeeees Loa RD sel eetely Soll Pils cll Aree 72 ere te Mtl ye ort pon i Pluteus podospileus 6 Pileus middle reticulate elevated, radially rugose........... Pluteus thomsonii - Pileus brown with stripes extending to the margins.......... Pluteus striatus 7 _ Pileipellis consists of globular, obpyriform, or spoheropedunculate cells ..8 - Pileipellis consists of without globular, obpyriform, or spheropedunculate WES t dior a ser rch Wee on Me orscoh ye RuCR IIE te ane ee Et breee ds Seren GOR te REE RISES ukomenc 16 Sill GLOWS OM FOTN G RV OO Gi, Be ht Sete a, ove crostini ecg tereublinS 9 — GIOWS ON NON-TOTHING WOOT ...............:cccceesceesseeeesseseresees Pluteus aletaiensis Oe *P ILEUS