Notes, taxonomy, and phylogeny of wood-inhabiting fungi in Russulales

Russulales Kreisel ex P.M. Kirk, P.F. Cannon & J.C. David is one of the significant fungal orders, comprising wood-inhabiting fungi within Agaricomycetes, Basidiomycota ^{[ 1− 4]} . The concept of Russulales was initially proposed in 1969, and later accepted and amended by Kirk ^{[ 4]} , and it was erected with the type family Russulaceae Lotsy ^{[ 4]} . Approximately 4,500 species have been ascribed to Russulales, which contains 98 genera, within 11 families ^{[ 1, 4− 7]} . Members of Russulales exhibit a wide range of ecological strategies including saprotrophic wood rotting, tree root and heartwood pathogens, ectomycorrhizal, and association with insects as entomogenous fungi ^{[ 4, 8]} . The genus Heterobasidion Bref. was indigenous to many areas and an important ecological factor involved in nutrient cycling, forest regeneration, and forest succession, such as Heterobasidion occidentale Otrosina & Garbel. and H. irregulare Garbel. & Otrosina as entry plant quarantine fungi in North America, and H. abietinum Niemelä & Korhonen, H. annosum (Fr.) Bref., and H. parviporum Niemelä & Korhonen as entry plant quarantine fungi in Europe ^{[ 4, 9− 13]} . Species of Albatrellus have been reported as significant ectomycorrhizal fungi ^{[ 4, 14]} . They also formed mutualistic symbiotic relationships with plants, especially Pinaceae ^{[ 4, 15]} , and some angiosperms ^{[ 4, 16]} , aiding in nutrient uptake and enhancing plant growth ^{[ 17]} . Albatrellus ovinus (Schaeff.) Kotl. & Pouzar is a common edible mushroom reported in Europe and North America ^{[ 17− 19]} .

Russulales is the most conspicuous and largest group of macrofungi, characterized by highly diverse basidiomata types which can range from agaricoid to discoid, clavarioid, polyporoid, corticiod, and even gasteroid ^{[ 1, 9− 11, 20− 22]} . Among Russulales, the hymenophore types encompass lamellate, hydnoid, poroid, labyrinthoid, grandinioid, and a smooth configuration ^{[ 17, 23, 24]} . Many species of Russulales share two key morphological characteristics: (1) basidiospore walls exhibit an amyloid reaction combined with an ornamented outline (although there are a few exceptions that have non-amyloid or smooth walls); (2) many of these species possess gloeoplerous hyphae or gloeocystidia containing sesquiterpenes that can be stained by sulphuric benzaldehydes ^{[ 25, 26]} . However, it is worth noting that in certain genera within the order, these elements may be absent or transformed into homologous structures like lactiferous hyphae ^{[ 1]} .

The morphology of the basidiomata and hymenophore, together with habitat, are often regarded as important characteristics of the order Russulales ^{[ 26− 28]} . Resupinate basidiomata are common in Echinodontiaceae Donk (=Amylostereaceae Boidin, Mugnier & Canales), Peniophoraceae Lotsy, Stereaceae Pilát and Terrestriporiaceae Y.C. Dai, B.K. Cui, F. Wu, Y. Yuan & Jia J. Chen, and rarely present in Hericiaceae Donk and Russulaceae Lotsy ^{[ 3, 21, 29− 34]} . Pileate basidiomata are predominantly found in Albatrellaceae Nuss, Auriscalpiaceae Maas Geest., Bondarzewiaceae Kotl. & Pouzar, Hericiaceae and Russulaceae; while gasteroid basidiomata are mainly present in Hybogasteraceae Jülich and Russulaceae, rarely in Albatrellaceae ^{[ 17, 35]} . Clavarioid basidiomata are present in Auriscalpiaceae, Bondarzewiaceae and Peniophoraceae, while effused-reflexed basidiomata are infrequently scattered in Auriscalpiaceae, Echinodontiaceae, Hericiaceae, Peniophoraceae, and Stereaceae ^{[ 1, 3, 12, 25, 28]} .

Fungal classification was traditionally based on comparative morphology, anatomy, biochemistry, physiology, and ecology ^{[ 2, 5, 6, 36, 37]} . The systematics of fungi has been revolutionized by advancements in molecular biology, phylogenetics, and bioinformatics. Nowadays, morphology integrated with DNA sequence-based classification and identification has become the standard approach in fungal taxonomy ^{[ 35, 38− 43]} . In the past few decades, evidence supporting the monophyly of Russulales has been gathered through both morphological characteristics and DNA sequence phylogenetic analyses ^{[ 1, 6, 10, 42]} . Miller et al. ^{[ 27]} first explored the molecular phylogeny of Russulales with an emphasis on the agaricoid, gasteroid and pleurotoid taxa in family Russulaceae, according to the current accepted classification ^{[ 25]} , which indicated that these taxa were not clustered strictly according to their basidiomata morphology. Larsson & Larsson ^{[ 26]} subsequently sampled some additional species producing corticioid basidiomata, and the resulting phylogeny suggested 13 major clades in the order with strong or moderate bootstrap support, as /peniophorales, /amylostereaceae, /gloeocystidiellum I, /gloeocystidiellum II, /auriscalpiaceae, /gloeodontia, /aleurocystidiellum, /hericiaceae, /bondarzewiaceae, /albatrellus, /scytinostromella, /russulales, and /stereales. Following these studies, Russulales was classified into 12 families and 80 genera on the basis of molecular and morphological characters. However, many taxa remain unsampled in phylogenetic analyses of Russulales, and phylogenies of many sampled taxa were not resolved. Some genera such as Gloeocystidiellum Donk and Wrightoporia Pouzar, are morphologically well defined, whereas they were inferred as polyphyletic or paraphyletic ^{[ 28]} . Previous research suggested that species of Wrightoporia s.l. were mainly placed in the Bondarzewiaceae clade, and the Wrightoporiaceae clade based on ITS and nLSU sequences ^{[ 10, 26, 44]} . Phylogenetic studies have supported the monophyletic status of only a few genera, such as Aleurocystidiellum P.A. Lemke and Wrightoporia, and these genera correspond to two families of their own ^{[ 11, 21, 45, 46]} . Other genera still require deeper analysis, since they were either intermixed with other taxa or possess or lack characters that intermingle with those present in other genera ^{[ 1, 19, 21, 46]} . Thus, the question remained as to whether to treat them in a broad or narrow sense ^{[ 46]} .

Some studies have shown a relatively constant relationship between differences in the amino acid sequences and divergence time of species ^{[ 47, 48]} . Recently, divergence time was used as an important criterion for the classification and estimation of evolutionary time of Basidiomycota ^{[ 1, 5, 13, 49− 51]} . The phylogenomic analysis suggested that the subphyla diverged in a time range of 443–490 Mya (million years), classes in a time range of 312–412 Mya, and orders in a time range of 102–361 Mya, families diverged in a time range of 50–289 Mya, 76–224 Mya, and 62–156 Mya in Agaricomycotina, Pucciniomycotina, and Ustilaginomycotina, respectively ^{[ 1]} . The Bayesian evolutionary analysis based on the combined ITS + nLSU + rpb1 + rpb2 + tef1- α dataset indicated an ancient divergence of the family Terrestriporiaceae from Albatrellaceae during the Cretaceous (124.68 ± 0.39 Mya (million years ago)) ^{[ 21]} . Nevertheless, there is no comprehensive study focused on the divergence times of Russulales and its lower classification ranking.

According to geographical regions, numerous new fungal species have been found in southwest China and low-latitude tropical and subtropical regions ^{[ 20]} . These regions have many hills and mountains, extensive vegetation coverage, a high fungi species richness, a mild climate, and abundant rainfall, all of which are conducive to fungal growth, and contribute to a rich species diversity ^{[ 20, 52]} . In recent years, several studies have been conducted on wood-inhabiting fungi in Yunnan Province, China ^{[ 20, 36, 51, 53, 54]} . However, there are still many new taxa that have not been discovered yet, due to the unique geographical environment and vegetation types in Yunnan Province. In this study, the taxon sampling of wood-inhabiting fungi is expanded to investigate taxonomy and phylogeny of new samples within Russulales collected from Yunnan Province. Based on a combination of morphological and molecular evidence of internal transcribed spacer (ITS) region, the large subunit nuclear ribosomal RNA gene (nLSU), the small subunit of mitochondrial rRNA gene (mtSSU), the second largest subunit of RNA polymerase II ( rpb2), and the translation elongation factor 1- α gene ( tef1- α) markers, two new families, a new genus, and 26 new species are proposed. The data available to date were used to construct a time-framed phylogenomic tree of Russulales. Based on the recent taxonomic revisions by He et al. ^{[ 1]} and Liu et al. ^{[ 42]} , and the updated classification of fungi (Outline of Fungi 2024) by Hyde et al. ^{[ 7]} , the currently recognized suborders, families, and number of genera within order Russulales are systematically presented in Table 1.

Fresh basidiomata of the fungi growing on angiosperm branches, and on the ground were collected from Dali, Dehong, Diqing, Honghe, Lincang, Lijiang, Puer, Qujing, Wenshan, Tengchong, Xishuangbanna, and Zhaotong in Yunnan Province, China. Voucher specimens were dried in an electric food dehydrator at 40 °C, and then deposited in the herbarium of the Southwest Forestry University (SWFC), Kunming, Yunnan Province, China. The samples were photographed in situ, and fresh macroscopic details were recorded. Photographs were recorded by a Jianeng 80D camera (Tokyo, Japan). All photos were stacked and merged using Helicon Focus Pro 7.7.5 software.

Morphological studies

Macromorphological descriptions and color terminology are based on field notes and photos captured in the field or laboratory, and follow those of a previous study ^{[ 36]} . Micromorphological characters were obtained from the dried specimens observed using a light microscope following a previous study ^{[ 36]} . The following abbreviations are used: KOH = 5% potassium hydroxide water solution, CB = cotton blue, CB– = acyanophilous, CB+ = cyanophilous, IKI = Melzer’s reagent, IKI+ = amyloid, IKI– = both inamyloid and indextrinoid, L = mean spore length (arithmetic average for all spores), W = mean spore width (arithmetic average for all spores), Q = variation in the L/W ratios between the specimens studied, and n = a/b (number of spores [a] measured from given number [b] of specimens) ^{[ 55]} .

Molecular procedures and phylogenetic analyses

The EZNA HP Fungal DNA Kit (Omega Biotechnologies Co., Kunming, China) was used with some modifications to extract DNA from the dried specimens. The DNA samples were kept at –20 °C. The thermal cycling conditions for each locus are provided in Table 2. The amplified fragments were internal transcribed spacer ITS (ITS5 and ITS4), the large subunit nuclear ribosomal RNA gene nLSU (LR0R and LR7), the small subunit of mitochondrial rRNA gene mtSSU (MS1 and MS2), the translation elongation factor 1- α gene tef1- α ( ef1-983 F and ef1-2218R), RNA polymerase II largest subunit rpb1 ( rpb1-Af and rpb1-Cf), and the second large subunit of RNA polymerase II rpb2 ( brpb2-6F and brpb2-7.1R) ^{[ 56− 60]} . The components of a 30 μL volume PCR mixture were 12.5 μL of double distilled water, 15 μL of PCR Master Mix (Sangon Biotech Shanghai Co., Shanghai, China), 1 μL of each primer and 1 μL of template DNA. The amplification followed the protocol of Dong et al. ^{[ 52]} . Amplified PCR products were examined through 1.5% agarose gel electrophoresis stained with GoldenView, and sent to Qingke Co., China, for sequencing. The PCR products were purified and sequenced at Kunming Tsingke Biological Technology Limited Company, Kunming, China. The sequences were reviewed and manually modified with Chromas v.1.0.1.1 to remove low-quality base calls from both ends. All newly generated sequences were subsequently deposited in GenBank ( Table 2).

The PCR protocol for ITS was as follows: initial denaturation at 95 °C for 3 min, followed by 35 cycles at 94 °C for 40 s, and 58 °C for 40 s. The PCR procedure for nLSU was as follows: initial denaturation at 94 °C for 1 min, followed by 35 cycles at 94 °C for 30 s, 48 °C for 1 min and, 72 °C for 1.5 min, and a final extension of 72 °C for 10 min. The PCR procedure for mtSSU was as follows: initial denaturation at 94 °C for 2 min, followed by 35 cycles at 94 °C for 45 s, 52 °C for 45 s and 72 °C for 1 min, and a final extension of 72 °C for 10 min. The PCR procedure for tef1- α was as follows: initial denaturation at 94 °C for 2.5 min, denaturation at 94 °C for 45 s, annealing at 60 °C for 50 s (minus 1 °C per cycle), extension at 72 °C for 2 min, repeat for 6 cycles starting at step 2, denaturation at 94 °C for 30 s, annealing at 55 °C for 50 s, extension at 72 °C for 1.5 min, repeat for 34 cycles starting at step 6, leave at 72 °C for 5 min. The PCR procedure for rpb1 was 94 °C for 2 min, followed by 10 cycles at 94 °C for 40 s, 60 °C for 40 s and 72 °C for 2 min, then followed by 37 cycles at 94 °C for 45 s, 55 °C for 1.5 min and 72 °C for 2 min, and a final extension of 72 °C for 10 min. The PCR procedure for rpb2 was 95 °C for 2.5 min, followed by 40 cycles at 95 °C for 30 s, 52 °C for 1 min, and 72 °C for 1 min, then followed by 40 cycles at 72 °C for 1.5 min, and final extension of 72 °C for 5 min ^{[ 20, 53]} . The PCR products were purified and sequenced at Kunming Tsingke Biological Technology Limited Company, Kunming, China. The newly generated fungal sequences in this study were deposited in GenBank.

Phylogenetic analyses

Phylogenetic analyses followed the methods described in Dissanayake et al. ^{[ 63]} . Newly generated sequence data were initially subjected to a BLAST search in NCBI to obtain the most probable closely related taxa in the GenBank ( http://blast.ncbi.nlm.nih.gov). Sequence data were retrieved from GenBank based on recent publications ( www.ncbi.nlm.nih.gov/nuccore). The sequences were aligned using MAFFT version 7 ^{[ 64]} with the G-INS-I strategy. The alignment was adjusted manually using AliView version 1.27 ^{[ 65]} . The dataset was initially aligned and later, ITS, nLSU, mtSSU, rpb2, and tef1- α sequences were combined using Mesquite version 3.51. FASTA data file formats were converted to NEXUS formats using the online tool available on the ALTER website ( http://sing.ei.uvigo.es/ALTER/) ^{[ 66]} . Phylogenetic trees were constructed based on randomized accelerated maximum likelihood (ML) and Bayesian inference (BI) analyses.

Maximum likelihood analysis was performed using the CIPRES Science Gateway ( www.phylo.org/portal2/login!input.action) ^{[ 67]} based on the dataset using the RA × ML-HPC BlackBox tool, with setting RA × ML halt bootstrapping automatically and 0.25 for maximum hours and obtaining the best tree using ML search. Other parameters in ML analysis used default settings, and statistical support values were obtained using nonparametric bootstrapping with 1,000 replicates. Bayesian inference analysis was performed on the dataset using MrBayes v3.2.7a ^{[ 68]} . The best substitution model for the dataset was selected by ModelFinder v2.2.0 ^{[ 69]} using a Bayesian information criterion, and the model was used for Bayesian analysis. Four Markov chains were run from random starting trees. Trees were sampled every 1,000 ^th generation. The first 25% of sampled trees were discarded as burn-in, while the remaining trees were used to construct a 50% majority consensus tree and to calculate Bayesian posterior probabilities (BPPs). Phylogenetic trees were visualized and adjusted using FigTree v1.4.0 ( http://tree.bio.ed.ac.uk/software/figtree), and the exports were edited using Adobe Illustrator CS6 software (Adobe Systems, USA). Branches of the consensus tree that received bootstrap support for ML equal to or above 70%, and BI equal to or above 0.95, are indicated.

Divergence time estimation

Three fossil calibrations, Archaeomarasmius leggetti Hibbett, D. Grimaldi and Donoghue, Quatsinoporites cranhamii S. Y. Sm., Currah and Stockey, and Paleopyrenomycites devonicus Taylor, Hass, Kerp, M. Krings and Hanlin, were used in the divergence time estimation. Archaeomarasmius leggetti was used as the representative of the minimum age of Agaricales at 90 Mya ^{[ 70]} ; Q. cranhamii was the representative of the minimum age of Hymenochaetaceae at 125 Mya ^{[ 52]} ; P. devonicus was used as the representative of the minimum age between Basidiomycota and Ascomycota at 400 Mya ^{[ 71, 72]} . Divergence time was estimated with the BEAST v2.6.5 software package with ITS, nLSU, rpb2 and tef1- α sequences representing main lineages in Basidiomycota ( Table 3). According to these time points, the offset age with a gamma distribution prior (scale = 20, shape = 1) for Agaricales was set as 90 Mya, and for Hymenochaetaceae as 125 Mya. After 20 million generations. The log file was analyzed in Tracer v1.6 to confirm that the estimated effective sample size (ESS) is ≥ 200 ³. The first 10% of the sampled trees every 1000 ^th generation were removed as burn-in. The resulting log file was checked for chain convergence using Tracer 1.5.

Genealogical concordance phylogenetic species recognition (GCPSR) analysis

The pairwise homoplasy index (PHI) test was conducted in certain cases of species delineation when necessary. We used the genealogical concordance phylogenetic species recognition analysis (GCPSR) to check for significant recombination events ^{[ 73]} . The data were analyzed using the PHI test in SplitsTree 4 to determine the recombination level with closely related species ^{[ 74− 76]} . ITS and LSU datasets with closely related species were used for the analyses. The pairwise homoplasy index lower than 0.05 (Φw ≤ 0.05) indicates significant recombination in the dataset. The relationships between closely related taxa were visualized by constructing split graphs from the concatenated datasets using the LogDet transformation and split decomposition options.

The aligned dataset encompassed 104 specimens representing 99 taxa. Cerioporus squamosus (Huds.) Quél. and Trametes suaveolens (L.) Fr. retrieved from GenBank were used as outgroup taxa ( Fig. 1) in previous analysis by Liu et al. ^{[ 88]} . Trees and parameters were sampled every 1,000 generations. ModelFinder v2.2.0 ^{[ 69]} was used to select the best-fit model based on the BIC criterion. The best model for the combined ITS, nLSU, mtSSU, rpb2, and tef1- α dataset was estimated as GTR + I + G, and it was applied in the Bayesian analysis. Maximum likelihood (ML) and Bayesian inference (BI) analyses yielded a similar topology, with an average standard deviation of split frequencies of 0.009610 (BI), and an effective sample size (ESS) average ESS (avg. ESS) = 754. The phylogram, based on the combined ITS + nLSU + mtSSU + rpb2 + tef1- α sequence analysis ( Fig. 1), showed that Russulales formed 13 distinct lineages, Albatrellaceae, Aleurocystidiellumaceae, Auriscalpiaceae, Bondarzewiaceae, Echinodontiaceae, Gloeocystidiellaceae, Gloeodontiaceae, Hericiaceae, Peniophoraceae, Russulaceae, Stereaceae, Terrestriporiaceae, and Wrightoporiaceae.

Figure 1. 

Maximum likelihood strict consensus tree illustrating the phylogeny of the species of Russulales based on ITS + nLSU + mtSSU + rpb2 + tef1- α sequences. Branches are labeled with maximum likelihood bootstrap values higher than 70%, and Bayesian posterior probabilities more than 0.95, respectively.

The divergence time of the order Russulales based on combined ITS + nLSU + rpb2 + tef1- α sequences data ( Fig. 2)

The ITS, nLSU, rpb2, and tef1- α dataset included 92 collections, of which 59 belonged to Russulales. This dataset resulted in a concatenated alignment of 5,419 characters with GTR + I + G as the best-fit evolutionary model. Chain convergence was indicated by the ESS 499. The result ( Fig. 2) showed that Russulales occurred in a mean crown age of 222.49 Mya (179.97–262.75 Mya, 95% HPD). The initial diversification between Hericiaceae and Aleurocystidiellaceae at 140.94 Mya (87.46–196.71 Mya, 95% HPD). The family Gloeodontiaceae occurred in a mean stem age of 178.7 Mya (139.36–218.13 Mya, 95% HPD). Subsequently, the new genus Subulicystidiella is grouped into family Echinodontiaceae and occurred in a mean stem age of 114.84 Mya (71.1–161.48 Mya, 95% HPD). The estimated divergence times for other nodes are summarized in Table 4.

Figure 2. 

Divergence time estimation of families within Russulales from molecular clock analysis sampling tree based on the combined sequence dataset of ITS, nLSU, rpb2, and tef1- α. Posterior probabilities not less than 0.80, and the mean ages of each node are annotated. The 90% highest posterior densities of divergence time estimation are marked by horizontal bars.

Family Gloeocystidiellaceae phylogeny based on combined ITS + nLSU sequences data ( Fig. 3)

The aligned dataset encompassed 43 specimens representing 20 taxa, including the two new species, Gloeocystidiellum membranaceum, G. punctatum, and Laurilia sulcata (Burt) Pouzar was retrieved from GenBank as an outgroup in using the concatenated ITS + nLSU sequences dataset analysis ( Fig. 3) following the previous study analysis ^{[ 89]} . The best fit model was estimated as TIM3ef + I + G for the ITS + nLSU dataset, and it was applied in the Bayesian analysis. Four Markov chains were run twice from a random starting tree, for 0.35 million generations of the datasets ( Fig. 3) with trees and parameters sampled every 1,000 generations. Both Bayesian analysis and ML analysis resulted in a similar topology to MP analysis with an average standard deviation of split frequencies = 0.009945 (BI), and the effective sample size (ESS) across the two runs is double of the average ESS (avg ESS) = 1224. The phylogram depicts an overall topology of the genus Gloeocystidiellum Donk ( Fig. 3) and reveals that G. membranaceum Y.L. Deng & C.L. Zhao, and G. punctatum Y.L. Deng & C.L. Zhao are grouped into this genus and G. membranaceum is retrieved as a sister to G. porosellum Hjortstam, and closely clustered with G. bisporum Boidin, Lanq. & Gilles. In addition, G. punctatum formed a separate clade.

Figure 3. 

Maximum likelihood strict consensus tree illustrating the phylogeny of two new species of Gloeocystidiellum based on ITS and nLSU sequences. Branches are labeled with maximum likelihood bootstrap values higher than 70%, and Bayesian posterior probabilities more than 0.95, respectively. The new species are in bold,, and type specimens are indicated with an asterisk (*).

Family Hericiaceae phylogeny based on combined ITS + nLSU sequences data ( Fig. 4)

The aligned dataset encompassed 75 specimens representing 53 taxa. Albatrellus ovinus (Schaeff.) Kotl. & Pouzar and A. subrubescens (Murrill) Pouzar were retrieved from GenBank as the outgroup taxa in using the concatenated ITS + nLSU sequences dataset analysis ( Fig. 4), following a previous analysis ^{[ 11]} . The estimated best fit model was GTR + I + G for the ITS + nLSU dataset, and it was applied in the Bayesian analysis. Four Markov chains were run twice from a random starting tree, for 0.25 million generations of the datasets ( Fig. 3) with trees and parameters sampled every 1,000 generations. Both Bayesian analysis and ML analysis resulted in a similar topology to MP analysis, with an average standard deviation of split frequencies = 0.009780 (BI), and the effective sample size (ESS) across the two runs is double of the average ESS (avg ESS) = 268.

The phylogram depicts an overall topology of family Hericiaceae ( Fig. 4), and shows that Dentipellis yingjiangensis and Laxitextum cremeum are grouped into genera Dentipellis Donk and Laxitextum Lentz, respectively. Dentipellis yingjiangensis Y.L. Deng & C.L. Zhao is retrieved as a sister to D. rhizomorpha Yuan Yuan & Y.C. Dai, and closely related to D. fragilis (Pers.) Donk, and D. dissita (Berk. & Cooke) Maas Geest. In addition, Laxitextum cremeum Y.L. Deng & C.L. Zhao is closely related to L. subrubrum R. Saha, A.K. Dutta & K. Acharya, L. bicolor (Pers.) Lentz, and L. incrustatum Hjortstam & Ryvarden. Furthermore, Subulicystidiella Y.L. Deng & C.L. Zhao clustered together within family Echinodontiaceae, and closely related to Larssoniporia Y.C. Dai, Jia J. Chen & B.K. Cui, and Amylostereum Boidin.

Figure 4. 

Maximum likelihood strict consensus tree illustrating the phylogeny of species of family Hericiaceae, and related families based on ITS and nLSU sequences. Branches are labeled with maximum likelihood bootstrap values higher than 70%, and Bayesian posterior probabilities more than 0.95, respectively. The new species are in bold, and type specimens are indicated with an asterisk (*).

Family Peniophoraceae phylogeny based on combined ITS and nLSU sequence data ( Fig. 5)

The aligned dataset encompassed 149 specimens representing 89 taxa. Stereum ostrea (Blume & T. Nees) Fr., and S. hirsutum (Willd.) Pers. were retrieved from GenBank as the outgroup taxa in the concatenated ITS + nLSU sequences dataset analysis ( Fig. 5) following the method of Deng et al. ^{[ 33]} . The estimated best fit model was GTR + I + G for the ITS + nLSU dataset, and it was applied in the Bayesian analysis. Four Markov chains were run twice from a random starting tree, for 7.66 million generations of the datasets ( Fig. 5) with trees and parameters sampled every 1,000 generations. Both Bayesian analysis and ML analysis resulted in a similar topology to MP analysis, with an average standard deviation of split frequencies = 0.010000, and the effective sample size (ESS) across the two runs is double of the average ESS (avg ESS) = 2,852.

Figure 5. 

Maximum likelihood strict consensus tree illustrating the phylogeny of species of family Peniophoraceae based on ITS and nLSU sequences. Branches are labeled with maximum likelihood bootstrap values higher than 70%, and Bayesian posterior probabilities more than 0.95, respectively. The new species are in bold, and type specimens are indicated with an asterisk (*).

The phylogram depicts an overall topology of family Peniophoraceae ( Fig. 5), and supports the introduction of 13 new species. Asterostroma fimbriatum Y.L. Deng & C.L. Zhao is grouped into Asterostroma, and retrieved as a sister to A. muscicola (Berk. & M.A. Curtis) Massee. Baltazaria pingbianensis Y.L. Deng & C.L. Zhao is grouped into Baltazaria, and closely related to B. galactina (Fr.) Leal-Dutra, Dentinger & G.W. Griff, and B. neogalactina (Boidin & Lanq.) Leal-Dutra, Dentinger & G.W. Griff. Two new species Gloiothele fragilima Y.L. Deng & C.L. Zhao, and G. tuberculata Y.L. Deng & C.L. Zhao are grouped into Gloiothele. They are sister to G. citrina (Pers.) Ginns & G.W. Freeman. and G. lamellosa (Henn.) Bres. and G. lactescens (Berk.) Hjortstam., respectively. Nine new Vararia species are grouped into genus Vararia, in which, V. asiana Y.L. Deng & C.L. Zhao is sister to V. daweishanensis L. Zou & C.L. Zhao, and closely related to V. rhombospora Boidin & Lanq; V. bambusicola Y.L. Deng & C.L. Zhao is sister to V. bannaensis Y.L. Deng & C.L. Zhao; V. ferruginosa Y.L. Deng & C.L. Zhao is related to V. cinnamomea Boidin, Lanq. & Gilles as a sister; V. lacerata Y.L. Deng & C.L. Zhao is sister to V. muscicola Y.L. Deng & C.L. Zhao; V. membranacea Y.L. Deng & C.L. Zhao is sister to V. punctata Y.L. Deng & C.L. Zhao; V. muscicola is sister to V. lacerata; V. pingbianensis is closely related to V. gomezii Boidin & Lanq., V. sigmatospora Boidin, Gilles & Lanq., and V. trinidadensis A.L. Welden. V. wumengshanensis Y.L. Deng & C.L. Zhao is grouped as sister to V. gallica (Bourdot & Galzin) Boidin .

Family Stereaceae phylogeny based on combined ITS and nLSU sequences data ( Fig. 6)

The aligned dataset encompassed 170 specimens representing 100 taxa. Laurilia sulcata was retrieved from GenBank as the outgroup taxon in the concatenated ITS+nLSU sequences dataset analysis ( Fig. 6) following a previous analysis ^{[ 87]} . The estimated best fit model was GTR + I + G for the ITS + nLSU dataset, and it was applied in the Bayesian analysis. Four Markov chains were run twice from a random starting tree, for 5.115 million generations of the datasets ( Fig. 6) with trees and parameters sampled every 1,000 generations. Both Bayesian analysis and ML analysis resulted in a similar topology to MP analysis with an average standard deviation of split frequencies = 0.009977, and the effective sample size (ESS) across the two runs is double of the average ESS (avg ESS) = 2255.

Figure 6. 

Maximum likelihood strict consensus tree illustrating phylogeny of species of family Stereaceae and related families based on ITS and nLSU sequences. Branches are labeled with maximum likelihood bootstrap values higher than 70%, and Bayesian posterior probabilities more than 0.95, respectively. The new species are in bold, and type specimens are indicated with an asterisk (*).

The phylogram depicts an overall topology of family Stereaceae ( Fig. 6), and eight new species are introduced. Aleurodiscus yunnanensis Y.L. Deng & C.L. Zhao is grouped within the genus Aleurodiscus and is closely related to A. wakefieldiae Boidin & Beller, and A. subroseus S.H. He & Y.C. Dai. Two new species, Confertotrama cremea Y.L. Deng & C.L. Zhao and C. yunnanensis Y.L. Deng & C.L. Zhao grouped with C. aspella (Hjortstam) Nakasone & S.H. He, C. rajchenbergii (Gorjón & Hallenb.) Nakasone & S.H. He, and C. rugulosa (Berk. & M.A. Curtis) Nakasone & S.H. He forming a clade. Gloeodontia sinensis Y.L. Deng & C.L. Zhao is grouped into Gloeodontia and closely related to G. columbiensis Burt ex Burds. & Lombard, and G. subasperispora (Litsch.) E. Larss. & K.H. Larss. Megalocystidium bambusinum Y.L. Deng & C.L. Zhao formed a separate lineage, closely related to M. effusum S.H. He and M. brunneum S.H. He. The three new species, Stereum convolutomarginatum Y.L. Deng & C.L. Zhao, S. rigidohymeneum Y.L. Deng & C.L. Zhao, and S. yunnanense Y.L. Deng & C.L. Zhao are grouped within the genus Stereum and closely related to S. ochraceoflavum (Schwein.) Sacc. and S. vellereum Berk., S. insigne Bres., and S. lobatum (Kunze ex Fr.) Fr., respectively.

Taxonomy:

Russulales Kreisel ex P.M. Kirk, P.F. Cannon & J.C. David

Family Albatrellaceae Nuss 1980

Index Fungorum number: IF80437

Type genus – Albatrellus Gray

Notes – Albatrellaceae is characterized by annual, resupinate, pileate-stipitate or gasteroid basidiomata, poroid or locular (gasteroid fungi) hymenophore, monomitic hyphal system, with or without clamp connections, inamyloid or amyloid hyphae, smooth or appearing slightly rough, with a double wall separated by interwall pillar or aleveolate, hyaline, inamyloid or amyloid basidiospores. Currently, eight genera are accepted in family Albatrellaceae ^{[ 1, 7, 17]} .

Note 1 Albatrellus Gray

Index Fungorum number: IF17035

Type species – Albatrellus albidus Gray 1821

Notes – Albatrellus is a mushroom genus belonging to Russulales, and holds a unique taxonomic status due to its poroid basidiomata ^{[ 16, 90]} . The important identifying features of Albatrellus are a poroid hymenophore of mostly white or cream colour, usually inflated hyphae, and smooth and mostly amyloid basidiospores. Initially, the taxonomy of Albatrellus was based on morphological studies, and the genus was treated as a polypore ^{[ 91− 93]} . Previous phylogenetic studies of Russulales revealed some Albatrellus species clustered in the russuloid clade ^{[ 26, 94, 95]} . The taxonomy of European and North American Albatrellus has been carried out by various mycologists ^{[ 15, 91− 93, 96]} . Recently, Zhou et al. ^{[ 17]} conducted multi-locus phylogenetic analyses based on seven gene loci (ITS, nLSU, tef1- α, rpb1, rpb2, mtSSU, and nucSSU), and showed that Albatrellus formed a polyphyletic group and belonged to family Albatrellaceae. Species within Albatrellus, specifically those in Albatrellus sensu stricto, are significant ectomycorrhizal fungi ^{[ 14]} . Some Albatrellus species also have edible and medicinal functions (antioxidative and antitumor activities), such as A. ovinus (Schaeff.) Kotl. & Pouzar which is a common edible mushroom in Europe and North America ^{[ 19, 97− 99]} . Based on Index Fungorum (2025), Albatrellus consists of 54 registered names of which 32 species are accepted worldwide.

Note 2 Byssoporia M.J. Larsen & Zak 1978

Index Fungorum number: IF17210

Type species – Byssoporia terrestris (DC.) M.J. Larsen & Zak 1978

Notes – Byssoporia was typified by B. terrestris (Pers.) M.J. Larsen & Zak, a genus proposed for Poria terrestris Pers. and its varieties ^{[ 100]} . It is characterized by effused basidiomata, basidia with 4 sterigmata, and ellipsoid to subglobose basidiospores ^{[ 100]} . Based on the MycoBank database (2025), and Index Fungorum (2025), Byssoporia has seven taxa, but only B. terrestris is accepted ^{[ 100]} . The species diversity of this genus needs to be further explored. Based on the ITS and nLSU dataset, the phylogeny of Russulales showed that Byssoporia grouped together with Albatrellus and Polyporoletus into family Albatrellaceae ^{[ 10]} .

Note 3 Polyporoletus Snell

Index Fungorum number: IF18333

Type species – Polyporoletus sublividus Snell

Notes – Polyporoletus inferred from the specific spores and typified by P. sublividus Snell. The genus is characterized by annual fascicular basidiomata, hymenophore with gray to bluish-gray or olive gray pores, monomitic hyphal system, cylindrical basidia and ellipsoid to subglobose basidiospores ^{[ 96]} . Based on the MycoBank database (2025), and Index Fungorum (2025), Polyporoletus has four species, P. bulbosus Audet, P. neotropicus M. Mata & Ryvarden, P. sublividus, and P. sylvestris (Overh. ex Pouzar) Audet. Based on morphological characteristics and the phylogenetic analysis of ITS1, 5.8S, ITS2 sequence data, Polyporoletus was closely related to Albatrellopsis Teixeira in family Albatrellaceae ^{[ 96]} .

Note 4 Family Aleurocystidiellaceae Y.L. Deng & C.L. Zhao, fam. nov.

Index Fungorum number: IF861354

Type genus – Aleurocystidiellum P.A. Lemke

Description – Basidiomata annual to perennial, cupulate to substereoid, margin determinate, subcoriaceous, hymenophore smooth, abhymenial sterile surface glabrous. Hyphal system monomitic or dimitic, generative hyphae with clamps. Basidia subclavate with 4-sterigmata and a basal clamp. Basidiospores ovoid to broadly ellipsoid, apiculate, thick-walled, minutely verruculose amyloid in Melzer's ^{[ 46, 101]} .

Notes – Lemke ^{[ 101]} proposed the genus Aleurocystidiellum, and it could not be assigned to any recognized family in Russulales. Rajchenberg et al. ^{[ 46]} proposed two new species combinations, A. bernicchiae (Gorjón, Gresl. & Rajchenb.) Rajchenb. & Pildain, and A. hallenbergii (Gorjón, Gresl. & Rajchenb.) Rajchenb. & Pildain based on morphology and phylogenetic analyses. However, a phylogenetic tree analysis indicated that Aleurocystidiellum formed a separate clade, and did not affiliate in any recognized family of Russulales. In this study, based on combined ITS + nLSU + rpb2 + tef1- α sequence dataset of Russulales in the phylogenetic analyses as well as the divergence time ( Figs 1, 2), Aleurocystidiellum formed a distinct lineage with strong support within Russulales. The divergence time of the Aleurocystidiellum clade is 140.94 Mya, with a 95% highest posterior density (HPD) of 87.46–196.71 Mya, 95% HPD. Therefore, the new family Aleurocystidiellaceae is introduced for this genus.

Note 5 Aleurocystidiellum P.A. Lemke 1964

Index Fungorum number: IF17039

Type species – Aleurocystidiellum subcruentatum (Berk. & M.A. Curtis) P.A. Lemke

Notes – Aleurocystidiellum was established by Lemke ^{[ 101]} to include dimitic species with discoid basidiomata and large, minutely verrucose, amyloid spores with A. subcruentatum (Berk. & M.A. Curtis) P.A. Lemke as the type species. Aleurocystidiellum subcruentatum was previously placed in Aleurodiscus based on its discoid basidiomata and the amyloid basidiospores ^{[ 101]} . Previously, Aleurodiscus disciformis (DC.) Pat. was transferred to Aleurocystidiellum ^{[ 26]} . Morphologically, A. disciforme (DC.) Tellería has moniliform gloeocystidia rather than skeletocystidia as in A. subcruentatum (Berk. & M.A. Curtis) P.A. Lemke, otherwise these two species are highly similar. The two species formed a distinct clade distant from Aleurodiscus s.s. in the phylogenetic trees in previous studies ^{[ 101− 103]} . Aleurodiscus tsugae Yasuda ex Lloyd was originally described from Japan on bark of Tsuga, and then found on Pinus in Japan, the Russian Far East and northeastern China ^{[ 102, 104]} . Careful morphological and molecular studies of the Chinese specimens of Aleurodiscus tsugae indicated that it belongs to the genus Aleurocystidiellum, and thus a new combination was proposed ^{[ 104]} .

Family Auriscalpiaceae Maas Geest. 1963

Index Fungorum number: IF80506

Type genus – Auriscalpium Gray

Notes – Auriscalpiaceae is characterized by annual, resupinate, effused-reflexed, pileate-sessile, pileate-stipitate to clavarioid basidiomata, hydnoid, poroid, labyrinthine to daedaleoid, meruloid and lamellate hymenophore. Monomitic to dimitic hyphal system, generative hyphae with clamp-connections, inamyloid or amyloid, skeletal hyphae when present dextrinoid ( Amylonotus), gloeoplerous hyphae and gloeocystidia present or absent, with asperulate, spinulose, verrucose, hyaline to pigmented, amyloid basidiospores. The species of this family are wood decaying or ectomycorrizal fungi ^{[ 1]} .

Note 6 Artomyces Jülich

Index Fungorum number: IF17104

Type species – Artomyces pyxidatus (Pers.) Jülich

Notes – Jülich ^{[ 105]} introduced Artomyces, and typified it with A. pyxidatus (Pers.) Jülich, proposing Artomyces as a distinct genus separate from Clavicorona Doty. Lickey et al. ^{[ 106]} conducted a comprehensive phylogenetic and taxonomic study for Artomyces, accepting 15 species within the genus based on a combination of morphology, nuclear ribosomal internal transcribed spacer DNA (nrITS DNA) sequences, and mating studies. In addition, they described seven new species. Kneal & Smith ^{[ 107]} described a new species A. nothofagi R.J. Kneal & M.E. Sm., based on morphology and phylogeny. Subsequently, Dong et al. ^{[ 52]} proposed two new species, A. niveus J.H. Dong & C.L. Zhao and A. yunnanensis J.H. Dong & C.L. Zhao, based on morphological and molecular evidence. Cai et al. ^{[ 108]} reported three new species, A. brunneoalbus Zhu L. Yang & Q. Cai, A. hirtipes Zhu L. Yang & Q. Cai, and A. pteruloides Zhu L. Yang & Q. Cai, based on morphological characteristics, ecological traits and molecular phylogenetic evidence in the family Auriscalpiaceae. To date, Artomyces consists of 24 registered names of which 22 species are accepted worldwide (Index Fungorum 2025).

Note 7 Auriscalpium Gray

Index Fungorum number: IF17139

Type species – Auriscalpium vulgare Gray

Notes – Auriscalpium (Auriscalpiaceae, Russulales) has about eight widely distributed species, and is characterized by pale to dark brown basidiocarps that are laterally to centrally stipitate and amyloid-ornamented basidiospores ^{[ 109]} . The genus is commonly known as 'the cone tooth', and A. vulgare is widely reported from the Northern Hemisphere ^{[ 109]} . It is the only known species of Auriscalpium which grows and reproduces on cones of various conifers; all other species inhabit soil or deadwood ^{[ 26, 109− 111]} . Wang & Yang ^{[ 112]} described two species, A. microsporum P.M. Wang & Zhu L. Yang, and A. orientale P.M. Wang & Zhu L. Yang inferred from morphological characteristics and molecular markers (ITS, nLSU, and rpb2). Currently, 19 species are accepted in Auriscalpium (Index Fungorum 2025).

Note 8 Dentipratulum Domański

Index Fungorum number: IF17488

Type species – Dentipratulum bialoviesense Domański

Notes – Domański ^{[ 113]} described the genus Dentipratulum with D. bialoviesense Domański to accommodate this mucronelloid fungus. Domański ^{[ 113]} placed Dentipratulum in family Hericiaceae, but the presence of sulfocystidia detected by Boidin & Gilles ^{[ 114]} indicated its affinity to family Auriscalpiaceae. The genus is characterized by basidiomata forming clusters of downwards-growing individual spines, scattered or crowded, pointed and unbranched; spines connected with very thin, rudimentary, discontinuous or continuous subiculum; monomitic hyphal system, generative hyphae with clamp connections, hyaline or rarely brownish in subiculum, thin to slightly thick-walled; gloeopleurous hyphae and presenting gloeocystidia, sulfopositive; clavate basidia with 2–4 sterigmata; and broadly ellipsoidal to globose basidiospores, slightly thick-walled, apiculate, ornamented, strongly amyloid, acyanophilous ^{[ 115]} . Macro-morphological similarities of the basidiomata of Dentipratulum and Mucronella Fr. are not reflected in their phylogenetic relationships, with Mucronella belonging to order Agaricales ^{[ 116]} . Based on the MycoBank database (2025), and Index Fungorum (2025), Dentipratulum has only three species, viz. D. bialoviesense Domański, found in the Białowieża Primeval Forest in Poland, and later reported from several locations in Eurasia; D. crystallinum Karasiński from the Kuril Islands and France; and D. khuranae Karasiński & Piątek from India ^{[ 116]} .

Note 9 Gloiodon P. Karst.

Index Fungorum number: IF17677

Type species – Gloiodon strigosus (Sw.) P. Karst.

Notes – Gloiodon was introduced by Karsten and typified by G. strigosus (Sw.) P. Karst. This genus is characterized by dark brown, effused-reflexed, or sessile basidiomata; spines with very dark but acquiring a whitish or bluish bloom from the ripening spores; dimitic hyphal system with thin-walled generative hyphae and clamp connections; clavate basidia with four spores, and a basal clamp; broadly ellipsoid basidiospores, minutely spinulose, and amyloid ^{[ 117, 118]} . Gloiodon includes five known species, G. hirtus (Fr.) P. Karst., G. nigrescens (Petch) Maas Geest., G. occidentalis Ginns, G. stratosus (Berk.) Banker and G. strigosus ^{[ 12]} . According to MycoBank and He et al. ^{[ 1]} , this genus belongs to family Bondarzewiaceae. However, based on the phylogenomic relationships and divergence times of combined ITS + nLSU + mtSSU + tef1- α+ rpb2 dataset Gloiodon grouped into Auriscalpiaceae.

Note 10 Family Bondarzewiaceae Kotl. & Pouzar 1957 (=Hybogasteraceae Jülich 1982)

Index Fungorum number: IF80527

Type genus – Bondarzewia Singer

Notes – The family Bondarzewiaceae was originally introduced to accommodate wood-rotting mushrooms, with type genus Bondarzewia Singer ^{[ 12, 21]} . Bondarzewiaceae is characterized by annual to perennial, resupinate, effused-reflexed, pileatesessile, pileate-stipitate to clavarioid basidiomata, smooth, tuberculate, poroid, hydnoid hymenophore. The hyphal system is monomitic, pseudodimitic to dimitic, generative hyphae with or without clamp-connections, inamyloid, skeletal hyphae inamyloid or dextrinoid ( Amylosporus), gloeoplerous hyphae and gloeocystidia present or absent, with asperulate, spinulose, verrucose, echinulate, ridges or crests, hyaline to pigmented, amyloid basidiospores. The family comprises wood decaying fungi ^{[ 1]} . Later, other genera, such as Amylaria Corner, Amylosporus Ryvarden, Heterobasidion Bref., and Echinodontium Ellis and Everh., were added to the family ^{[ 26]} . However, it was was later suggested that Echinodontium is sister to Amylostereum Boidin and it has been treated under Echinodontiaceae Donk ^{[ 45, 94, 119]} . Members of this family are widespread and found in tropical, subtropical, and temperate climates ^{[ 1]} . Ecologically, these species are mostly associated with wood as decaying fungi; however, some such as Bondarzewia berkeleyi (Fr.) Bondartsev and Singer, B. montana (Quél.) Singer, Heterobasidion annosum (Fr.) Bref., and H. parviporum Niemelä and Korhonen, are plant pathogens ^{[ 1, 5, 45, 120, 121]} .

Note 11 Amylaria Corner

Index Fungorum number: IF17062

Type species – Amylaria himalayensis Corner

Notes – Amylaria, typified by A. himalayensis. It is characterized by clavarioid basidiomata, hyphal system dimitic with clamped generative hyphae, clavate to subventricose basidia with 2–4 sterigmata and amyloid ellipsoidal basidiospore ^{[ 1, 25]} Amylaria is a monotypic, clavorioid genus reported from Bhutan and Nepal ^{[ 25]} . The genus has been placed in Bondarzewiaceae according to recent systematics reports ^{[ 1]} . However, Hussain et al. ^{[ 12]} declared that the systematic position of this taxon in Bondarzewiaceae is questionable due to lack of sequence data and limited reports of the genus have been made after the original description.

Note 12 Amylonotus Ryvarden

Index Fungorum number: IF17069

Type species – Amylonotus africanus Ryvarden

Notes – Amylonotus was proposed by Ryvarden ^{[ 122]} based on A. africanus, but species in the genus were later treated in Wrightoporia by David & Rajchenberg ^{[ 123]} . A phylogeny based on ITS + nLSU sequence data revealed that A. labyrinthinus (= Wrightoporia labyrinthina T. Hatt.), and A. africanus (= W. pouzarii A. David & Rajchenb.) formed a well-supported lineage within family Bondarzewiaceae clade, distant from W. lenta (Overh. & J. Lowe) Pouzar, and closely related to species of Bondarzewia Singer and Heterobasidion Bref. ^{[ 10, 11]} . Amylonotus is characterized by its effused-reflexed or resupinate, sessile, pileate, soft coriaceous to brittle basidiomata with cinnamon to dark brown pileal surface; pale orange, isabelline, pale cinnamon to brown pore surface; hyphal system dimitic with clamped generative hyphae; thin- to slightly thick-walled, ellipsoid to subglobose, finely asperulate basidiospores ^{[ 122]} . Five species have been recorded in Amylonotus, viz. A. africanus Ryvarden, A. gyroporus (Corner) Y.C. Dai, Jia J. Chen & B.K. Cui, A. labyrinthinus (T. Hatt.) Y.C. Dai, Jia J. Chen & B.K. Cui, A. ramosus (A. David & Rajchenb.) Y.C. Dai, Jia J. Chen & B.K. Cui and A. tenuis G.Y. Zheng & Z.S. Bi ^{[ 10, 11, 122, 123]} .

Note 13 Amylosporus Ryvarden

Index Fungorum number: IF17072

Type species – Amylosporus graminicola (Murrill) Ryvarden

Notes – Amylosporus was introduced in 1973, initially typified with A. graminicola ^{[ 124]} . Later, A. graminicola was synonymized with A. campbellii (Berk.) Ryvarden, with the latter becoming the type species of the genus, introduced to include species having both simple septate and multi-clamped generative hyphae, and finely asperulate and amyloid basidiospores ^{[ 125]} . Amylosporus wrightii Rajchenb. is a taxonomic synonym of A. bracei (Murrill) A. David & Rajchenb. Based on ITS + nLSU sequence data and morphological characteristics, Chen et al. ^{[ 10]} proposed that Wrightoporia casuarinicola Y.C. Dai & B.K. Cui, W. efibulata I. Lindblad & Ryvarden and W. rubella Y.C. Dai are characterized by their generative hyphae lacking clamp connections, which fits the newly defined Amylosporus (clamp connections are absent in hymenium). Currently, there are 14 species of Amylosporus, namely A. annosus Y.C. Dai, P. Du & X.H. Ji, A. auxiliadorae Drechsler-Santos & Ryvarden, A. bracei (Murrill) A. David & Rajchenb., A. campbellii, A. casuarinicola (Y.C. Dai & B.K. Cui) Y.C. Dai, Jia J. Chen & B.K. Cui, A. daedaliformis G.Y. Zheng & Z.S. Bi, A. efibulatus, A. guaraniticus Campi & Robledo, A. rubellus, A. ryvardenii Stalpers, A. succulentus Jia J. Chen & L.L. Shen, A. sulcatus F.C. Huang & Bin Liu, A. wadinaheezicus S. Hussain, Al-Sadi, Al-Yahya'ei, Al-Kharousi & Al-Owaisi, A. wrightii Rajchenb. ^{[ 10, 12, 126]} . Initially, the genus was placed in Wrightoporiaceae Jülich, but recently it was treated under Bondarzewiaceae ^{[ 1, 5, 12, 121]} .

Note 14 Bondarzewia Singer

Index Fungorum number: IF17176

Type species – Bondarzewia montana (Quél.) Singer

Notes – Bondarzewia was established based on B. montana, now considered a synonym of B. mesenterica (Schaeff.) Kreisel, originally described from Abies in the Pyrenees mountains ( B. mesenterica in Germany). It is a remarkable genus because the species usually have relatively large and imbricate basidiomata. Some species are edible and have medicinal potential, such as B. mesenterica ^{[ 11, 12, 14, 127, 128]} , while others are plant pathogens ^{[ 120]} . The genus is characterized by annual growth habit, pileate basidiomata with poroid hymenophores and it is morphologically similar to many species of order Polyporales. However, it has strongly amyloid and ornamented basidiospores and recent phylogenetic analyses revealed that it belongs to Russulales ^{[ 12, 26, 28, 45, 128, 129]} . Chen et al. ^{[ 11]} conducted a taxonomic study of Bondarzewia based on many samples covering a wide geographic range. With the aid of morphological and phylogenetic analyses of ITS and nuc 28S rDNA D1-D2 domain (28S) sequences, three new species were described and three new combinations were proposed ^{[ 11]} . Hussain et al. ^{[ 12]} estimated the divergence time of Bondarzewiaceae (Russulales) based on ITS-28S dataset, revealed that the species diversified approximately 114 million years ago (Mya). The clade consisted of Bondarzewia, Heterobasidion, Gloiodon, Laurilia, Lauriliella, and Wrightoporia, which estimated stem age of the clade is approximately 90 Mya.

Note 15 Heterobasidion Bref.

Index Fungorum number: IF17745

Type species – Heterobasidion annosum (Fr.) Bref.

Notes – Heterobasidion was typed by H. annosum. It is characterized by effused-reflexed to sessile basidiomata, dimitic hyphal system with dextrinoid skeletal hyphae, generative hyphae without clamp connections, and finely asperulate and nonamyloid basidiospores, and is distributed in both Northern and Southern Hemispheres ^{[ 9]} . Based on ITS, nLSU, rpb1, rpb2, gapdh, atp6, and mtSSU, Chen et al. ^{[ 13]} suggested that ancestral Heterobasidion species originated in Eurasia during the Early Miocene, followed by dispersal and speciation to other continents during the Middle Miocene and Early Pliocene. Heterobasidion is a global complex of woody plant pathogens and saprobes whose host range comprises over 200 plant taxa, most of which are conifers ^{[ 13]} . Heterobasidion has a negative impact on conifers, both ecologically and economically, by reducing site productivity and the amount of harvestable timber ^{[ 9, 12]} . Heterobasidion abietinum Niemelä and Korhonen, distributed in Italy, is associated with Abies alba and Picea abies; H. amyloideum Y.C. Dai, Jia J. Chen and Korhonen with Abies in China; H. annosum from Italy and Russia, associated with different species of Pinus; H. araucariae P.K. Buchanan with trees of Araucaria cunninghamii, reported from Australia; H. armandii Y.C. Dai, Jia J. Chen and Yuan Yuan with Pinus armandii, found in China; H. australe Y.C. Dai and Korhonen from China, associated with Pinus species; H. insulare (Murrill) Ryvarden from China in association with Pinus massoniana; H. irregulare Garbel. and Otrosina is a South American species associated with Pinus; H. linzhiense Y.C. Dai and Korhonen is a Chinese species associated with Abies and Picea; H. occidentale is pathogenic to various conifer hosts; H. orientale Tokuda, T. Hatt. and Y.C. Dai associated with fallen conifer trunk, reported from China; H. parviporum Niemelä and Korhonen associated with Picea abies, distributed in Europe and Asia; H. subinsulare Y.C. Dai, Jia J. Chen and Yuan Yuan is reported from China, associated with wood of Pinus; H. subparviporum Y.C. Dai, Jia J. Chen and Yuan Yuan with wood of Abies and Picea, reported from China; and H. tibeticum Y.C. Dai, Jia J. Chen and Korhonen with Pinus wood from China ^{[ 9, 12]} .

Note 16 Laurilia Pouzar

Index Fungorum number: IF17912

Type species – Laurilia sulcata (Burt) Pouzar

Notes – Laurilia is a monotypic genus with L. sulcata, characterized by effuse-reflexed basidiomata with smooth to tuberculate hymenophore, and a trimitic hyphal system ^{[ 81]} . Laurilia sulcata is widely distributed in boreal conifer forests in the northern hemisphere ^{[ 81]} . It is characterized by having basidiomata of perennial, leathery or ligneous, resupinate, effused and confluent, or partly pileate, especially on vertical sides of the substrate; hyphal system is trimitic with skeletals and binding hyphae with thick walls and few clamps, and thin-walled, fibulate generative hyphae; tinder-layer mainly dimitic, composed largely of horizontal, brown, thick-walled skeletal hyphae; metuloid cystidia numerous, thick-walled, encrusted; clavate basidia with 4 sterigmata and basal clamp; and globose spores, somewhat thick-walled, echinulate and amyloid ^{[ 130]} . Only two species, L. sulcata and L. taxodii (Lentz & H.H. McKay) Pouzar are accepted (Index Fungorum 2025).

Note 17 Lauriliella S.H. He & Nakasone

Index Fungorum number: IF819211

Type species – Lauriliella taxodii (Lentz & H.H. McKay) S.H. He & Nakasone

Notes – Lauriliella was established by He & Nakasone, and typified by L. taxodii (= Stereum taxodii Lentz & H.H. McKay). It is a perennial genus with effused-reflexed, pileate or umbonate, woody basidiomata, hymenophore smooth to tuberculate, basidia with basal clamp connections, basidiospores broadly ellipsoid to subglobose, hyaline, thick-walled, echinulate, and amyloid ^{[ 81]} . The genus comprises two species, L. taxodii and L. taiwanensis S.H. He and Nakasone. Lauriliella taxodii is distributed in USA, causing white stringy rot or brown powdery rot in living Taxodium distichum. Similarly, L. taiwanensis is reported from China, causing white rot in living Chamaecyparis formosensis ^{[ 81]} . With the transfer of Laurilia taxodii into Lauriliella, Laurilia becomes monotypic. Although similar, Laurilia and Lauriliella can be distinguished by several critical features. Laurilia causes a white stringy rot or white pocket rot in dead coniferous wood, whereas Lauriliella creates large pockets of decayed wood scattered in the heartwood of Taxodium and Chamaecyparis which is somewhat stringy or laminated. The hymenophore is light yellow or pink to salmon-colored in Laurilia but gray, orange, or brown in Lauriliella. Microscopically, unbranched skeletal hyphae are dominant in the context of Lauriliella, whereas in Laurilia unbranched skeletals and richly branched binding hyphae are present. Davidson et al. ^{[ 131]} and Nakasone ^{[ 132]} noted the differences in cultures, with L. sulcata growing faster, producing strong oxidase reactions, and developing conidia (Spiniger anamorph). In contrast, L. taxodii cultures grew very slowly and produced no or weak oxidase reactions and produced chlamydospores.

Note 18 Stecchericium D.A. Reid

Index Fungorum number: IF18581

Type species – Stecchericium fistulatum (G. Cunn.) D.A. Reid

Notes – Stecchericium was established by D.A. Reid based on S. seriatum (Lloyd) Maas Geest. (= S. fistulatum G. Cunn.) as the type. It is characterized by pileate basidiomata, hydnoid hymenophore, monomitic to imperfectly dimitic hyphae system, tubular and thick-walled gloeocystida, and finely asperulate, strongly amyloid basidiospores ^{[ 133]} . This genus resembles Steccherinum Gray in macroscopic characters, and they could be easily confused with each other in the field. But Steccherinum has encrusted skeletocystidia and smooth, non-amyloid basidiospores ^{[ 133]} . According to MycoBank, Stecchericium belongs to Wrightoporiaceae; however, recent studies ^{[ 1, 5, 134]} classified it in Bondarzewiaceae. The known species are S. abditum Maas Geest., found on rotten log in Australia, S. acanthophysium T. Hatt. and Ryvarden on hardwood reported from Japan, S. isabellinum Corner associated with fallen wood in the Amazon forest, S. rusticum Maas Geest., on dead wood in Singapore, S. seriatum were found in Singapore and Malaysia, and S. dimiticum Douanla-Meli associated with angiosperm wood, reported from Cameroon ^{[ 135]} .

Family Echinodontiaceae Donk 1961

Index Fungorum number: IF80722

Type genus – Echinodontium Ellis & Everh.

Notes – Echinodontiaceae is characterized by annual to perennial, resupinate, effused-reflexed to pileate-sessile basidiomata, smooth, poroid to hydnoid hymenophore, monomitic, pseudodimitic to dimitic hyphal system, generative hyphae with or without clamp-connections, inamyloid, skeletal hyphae inamyloid or dextrinoid ( Larssoniporia), gloeocystidia present or incrusted cystidia absent or present, with smooth, asperulate, spinulose, verrucose, hyaline to pigmented, amyloid basidiospores. This family consists of wood decaying fungi ^{[ 1]} .

Note 19 Amylostereum Boidin

Index Fungorum number: IF17073

Type species – Amylostereum chailletii (Pers.) Boidin

Notes – Amylostereum with A. chailletii as its type is a fascinating genus, as some species are symbionts of mycophagus horntails ^{[ 136]} . Species are characterized by numerous thick-walled and apically encrusted cystidia in hymenium and context, nodose-septate generative hyphae and distinctly amyloid basidiospores ^{[ 137]} . Six species, A. areolatum (Chaillet ex Fr.) Boidin, A. chailletii, A. ferreum (Berk. & M.A. Curtis) Boidin & Lanq., A. laevigatum (Fr.) Boidin, A. orientale S.H. He & Hai J. Li, A. stillwellii Slippers, K.N.E. Fitza & J.D. Allison, are recognized worldwide, all associated with gymnosperm hosts ^{[ 138− 140]} . Traditionally, Amylostereum has been placed in family Stereaceae due to its morphological similarity to Stereum Hill ex Pers. ^{[ 141, 142]} . However, phylogenetic analysis based on DNA sequences showed that Amylostereum is close to Echinodontium Ellis & Everh. and should be placed in the monotypic family Amylostereaceae ^{[ 138, 139]} . However, divergence times showed that Amylostereum was placed in family Echinodontiaceae ^{[ 1]} . The present study, based on the ITS, nLSU, mtSSU, rpb2, and tef1- α dataset, confirmed that Amylostereum formed an independent lineage in Echinodontiaceae.

Note 20 Echinodontiellum S.H. He & Nakasone

Index Fungorum number: IF819204

Type species – Echinodontiellum japonicum (Imazeki) S.H. He & Nakasone

Notes – Echinodontiellum was established by S.H. He & Nakasone to accommodate E. japonicum (= Echinodontium japonicum Imazeki). It is characterized by perennial, resupinate to slightly effused-reflexed basidiomata, gray to olive gray and dentate hymenophore, dimitic hyphal system, thin- to thick-walled generative hyphae nodose-sepatate, with scattered secondary simple septa, thick-walled to subsolid skeletal hyphae light brown, clavate, hyaline to light brown, thick-walled cystidia apically encrusted, blunt, embedded or slightly projected, clavate basidia with four sterigmata, and a basal clamp connection, and ellipsoid, thick-walled, echinulate, amyloid basidiospores ^{[ 81]} . Morphological differences between Echinodontium Ellis & Everh and Echinodontiellum are few but significant. Basidiomata of Echinodontiellum are effused to effused-reflexed, whereas they are effused-reflexed to pileate, rarely effused, in Echinodontium. The context in Echinodontiellum is cinnamon to olive gray or brownish gray that darkens in KOH. In comparison, the context of Echinodontium species are brick red or brownish orange turning maroon in KOH or pale brown to brown (in Echinodontium ryvardenii Bernicchia & Piga). Furthermore, Echinodontiellum japonicum is sister to Echinodontium s.s. and segregated into a separate genus because of ecological, basidiomata, and molecular criteria ^{[ 81]} .

Note 21 Echinodontium Ellis & Everh.

Index Fungorum number: IF17540

Type species – Echinodontium tinctorium (Ellis & Everh.) Ellis & Everh.

Notes – Species of Echinodontium sensu lato are characterized by conspicuous basidiomata, dentate to smooth hymenophores, encrusted cystidia, and ornamented, amyloid basidiospores ^{[ 81]} . Based on a concatenated dataset of ITS and 28S sequences of taxa in Russulales, E. tinctorium, E. tsugicola (Henn. & Shirai) Imazeki, and E. ryvardenii were confirmed in family Echinodontiaceae ^{[ 81]} . Echinodontium sulcatum (Burt) H.L. Gross and E. taxodii (Lentz & H.H. McKay) H.L. Gross were also placed in Laurilia Pouzar and Lauriliella S.H. He & Nakasone in some studies ^{[ 81, 143]} . Currently, only five species, E. ballouii (Banker) H.L. Gross, E. japonicum Imazeki, E. ryvardenii, E. tinctorium, and E. tsugicola are accepted (Index Fungorum 2025). Tabata et al. ^{[ 138]} demonstrated that Echinodontium and Amylostereum were phylogenetically related, and belonged in Echinodontiaceae. This was confirmed by subsequent studies ^{[ 10, 81, 94, 144, 145]} .

Note 22 Larssoniporia Y.C. Dai, Jia J. Chen & B.K. Cui

Index Fungorum number: IF812223

Type species – Larssoniporia tropicalis (Cooke) Y.C. Dai, Jia J. Chen & B.K. Cui

Notes – Larssoniporia was proposed to accommodate L. tropicalis ( Wrightoporia tropicalis (Cooke) Ryvarden) and L. incrustatocystidiata Y.C. Dai, Jia J. Chen & B.K. Cui ^{[ 10]} . Larssoniporia is characterized by its woody hard basidiomata with tough tubes, dextrinoid skeletal hyphae, presence of cystidia with crystals at tips, and gloeocystidia, finely asperulate and amyloid basidiospores, and is tropical in distribution ^{[ 10]} . Phylogeny of Russulales inferred from ITS and 28S sequence data, placed Larssoniporia into family Echinodontiaceae ^{[ 81]} .

Note 23 Subulicystidiella Y.L. Deng & C.L. Zhao gen. nov.

Index Fungorum number: IF861371

Type species – Subulicystidiella murina Y.L. Deng & C.L. Zhao.

Etymology – referring to the subulate cystidia of the type species.

Notes – Subulicystidiella is characterized by annual, resupinate, membranous basidiomata, closely adnate, smooth, gray to charcoal gray hymenial surface, a monomitic hyphal system, thin-walled, generative hyphae with clamp connections, subulate, yellowish brown, thick-walled, cystidia with acute tips, encrusted with crystals in the apical part, thin-walled, smooth, barrelled cystidia with a clamp connection at base, cylindrical basidia with four sterigmata and a basal clamp connection thin-walled, smooth, globose basidiospores. Our study, based on ITS + nLSU + mtSSU + rpb2 + tef1- α sequence data and ITS + nLSU sequence data, showed that Subulicystidiella clustered within family Echinodontiaceae, closely related to Larssoniporia and Amylostereum, and formed a separate clade. However, morphologically, Larssoniporia differs from Subulicystidiella by its hard basidiomata with tough tubes, hyphal system dimitic, dextrinoid skeletal hyphae, and finely asperulate basidiospores ^{[ 10]} . Amylostereum can be distinguished from Subulicystidiella by its thick-walled and apically encrusted cystidia in hymenium and context, nodose-septate generative hyphae and distinctly amyloid basidiospores ^{[ 10]} . Thus, a new genus Subulicystidiella is introduced, based on phylogenetic analyses and morphological characteristics ( Figs. 7, 8).

Subulicystidiella murina Y.L. Deng & C.L. Zhao, sp. nov. Figures 7, 8

Index Fungorum number: IF861374

Figure 7. 

Basidiomata and microscopic structures of Subulicystidiella murina (holotype). (a) Basidiomata on the substrate. (b) Section of hymenophore. (c) Basidiospores. (d) Basidia and basidioles. (e) Barrelled gloeocystidia. (f) Subulate cystidia (g) Section of hymenium. Scale bars: (a) = 1 cm, (b) = 1 mm, (c) = 5 µm, (d)–(g) = 10 µm.

Figure 8. 

Sections of hymenium of Subulicystidiella murina (holotype). (a) Basidiospores. (b) Basidia and basidioles. (c) Barrelled cystidia. (d) Subulate cystidia. Scale bars: (a)–(d) = 10 µm.

Diagnosis – Subulicystidiella murina differs from other species by the membranous basidiomata, gray to charcoal gray hymenial surface, hyphal system monomitic with clamped generative hyphae, and globose basidiospores.

Etymology – referring to the murine hymenial surface of the type specimens.

Type – China, Yunnan Province, Xishuangbanna, Wild Elephant Valley, 22°17′ N, 100°85′ E, 900 m asl, on fallen angiosperm branch, leg. C.L. Zhao, 25 January, 2024, CLZhao 35801 (SWFC).

Description – Basidiomata annual, resupinate, membranous, closely adnate, thin, without odor or taste when fresh, up to 5.5 cm long, 1.5 cm wide, 150 µm thick. Hymenial surface smooth, gray when fresh, gray to charcoal gray upon drying. Sterile margin gray, thinning out, up to 1 mm wide.

Hyphal system monomitic; generative hyphae with clamp connections, colorless, thin-walled, smooth, moderately branched, 2.5–5.5 µm in diameter, IKI–, CB–; tissues unchanged in KOH. Cystidia with two types: (1) subulate cystidia, numerous, some slightly sigmoid, yellowish brown, thick-walled, with acute tips, encrusted with crystals in the apical part, 18–60 × 7–49 µm, projecting up to 36 µm above the hymenium; (2) barrelled cystidia, colorless, thin-walled, smooth, filled with refractive material, with a clamp connection at base, 41–57 × 6–10 µm. Basidia cylindrical, with one oil drop, four sterigmata, and a basal clamp connection, 20–34 × 5–8.5 µm; basidioles numerous, in shape similar to basidia but smaller. Basidiospores globose, colorless, thin-walled, smooth, with some oil drops, CB–, IKI–, (5.3–)5.7–7.4(–7.8) × (4.3–)4.6–6.3(–6.9) µm, L = 6.42 µm, W = 5.55 µm, Q = 1.16 (n = 60/2).

Additional material examined – China, Yunnan Province, Dehong, Yingjiang County, Tongbiguan Provincial Nature Reserve, 24°71′ N, 94°52′ E, 1,500 m asl, on fallen angiosperm branch, leg. C.L. Zhao, 21 July 2023, CLZhao 30728 (SWFC).

GenBank accession numbers – CLZhao 35801 ITS: PV441140, LSU: PV441154, mtSSU: PV461163; CLZhao 30728 ITS: PV771055, LSU: PX418375, mtSSU: PV774692.

Family Gloeocystidiellaceae Jülich 1982

Index Fungorum number: IF81775

Type genus – Gloeocystidiellum Donk

Notes – Gloeocystidiellaceae is characterized by annual resupinate, effused-reflexed basidiomata, smooth, rarely grandinioid or odontioid hymenial surface, a monomitic hyphal system with nodose or simple-septate generative hyphae, gloeocystidia, subcylindrical to clavate basidia with four sterigmata and suballantoid, ellipsoid, subglobose or globose, verrucose or aculeate basidiospores ^{[ 45]} .

Note 24 Gloeocystidiellum Donk

Index Fungorum number: IF17663

Type species – Gloeocystidiellum porosum (Berk. & M.A. Curtis) Donk

Notes – A corticioid genus Gloeocystidiellum belonging to order Russulales was established by Donk with G. porosum as its type species. The genus is characterized by smooth, rarely grandinioid or odontioid hymenial surface, a monomitic hyphal system with nodose or simple-septate generative hyphae, gloeocystidia, subcylindrical to clavate basidia with four sterigmata and suballantoid, ellipsoid, subglobose or globose, verrucose or aculeate basidiospores ^{[ 146]} . Recently, molecular studies involving Gloeocystidiellum based on single-gene or multi-gene datasets have been carried out ^{[ 3, 147− 151]} . Phylogenetic relationships of russuloid basidiomycetes revealed that the species of Gloeocystidiellum formed two clades based on analyses of nuclear 5.8S, ITS2, and nLSU rDNA genes, in which the generic type species G. porosum grouped into clade I ^{[ 26]} . The high phylogenetic diversity among corticioid homobasidiomycetes showed that G. subasperisporum (Litsch.) J. Erikss. & Ryvarden nested into the russuloid clade and closely grouped with Gloeodontia discolor (Berk. & M.A. Curtis) Boidin ^{[ 116]} . Phylogenetic relationships inferred from 5.8S and nuLSU rDNA sequences showed that Gloeocystidiellum is clustered into family Gloeocystidiellaceae and closely related to Russulaceae within Russulales ^{[ 45]} . Analyses based on ITS and nLSU sequences indicated that Gloeocystidiellum clustered with Russulaceae Lotsy and Gloeodontia clade ^{[ 82, 150]} . In this study, analyses inferred from ITS + nLSU + mtSSU + rpb2 + tef1- α sequences ( Figs 1, 3) showed that Gloeocystidiellum is polygeneic, formed two single clades and then grouped with Gloeodontia clade and Russulaceae. Thus, Gloeocystidiellum is placed into family Gloeocystidiellaceae. Also, two new species, G. membranaceum and G. punctatum found in China are introduced, based on phylogeny and morphological characteristics.

Gloeocystidiellum membranaceum Y.L. Deng & C.L. Zhao, sp. nov. Figures 9, 10

Index Fungorum number: IF860765

Figure 9. 

Basidiomata and microscopic structures of Gloeocystidiellum membranaceum (holotype). (a) Basidiomata on the substrate. (b) Section of hymenophore. (c) Basidiospores. (d) Gloeocystidia. (e) Basidioles. (f) Basidia. (g) Section of hymenium. Scale bars: (a) = 1 cm, (b) = 1 mm, (c) = 5 µm, (d)–(g) = 10 µm.

Figure 10. 

Sections of hymenia of Gloeocystidiellum membranaceum (holotype). (a)–(c) Basidiospores and basidia. (d) Gloeocystidia. (e) Hyphae from context. (f) Section of hymenium. Scale bars: (a)–(f) = 10 µm.

Diagnosis – Differs other species by the white to cream, smooth hymenial surface, a dimitic hyphal system with clamped generative hyphae, cylindrical basidia, and ellipsoid basidiospores.

Etymology – referring to the membranous hymenial surface of the type specimen.

Type – China, Yunnan Province, Dehong, Mang City, Tongbiguan Provincial Nature Reserve, 25°50′ N, 97°36′ E; 1,000 m asl, on fallen angiosperm branch, 30 June, 2024, CLZhao 37038 (SWFC).

Description – Basidiomata annual, resupinate, closely adnate, membranous, without odor or taste when fresh, up to 10 cm long, 1 cm wide, and 150 µm thick. Hymenial surface smooth, white to cream when fresh, buff to pale brown upon drying. Sterile margin thin, white, up to 1 mm.

Hyphal system monomitic, generative hyphae bearing simple septa, colorless, thin-walled, branched, 2.5–4.5 µm in diameter, IKI–, CB–; tissues unchanged in KOH. Gloeocystidia abundant, cylindrical, basally inflated and slightly tapering towards the apices, thin-walled, 26.5–72.5 × 6–12.5 µm. Basidia cylindrical, colorless, thin-walled, with a basal simple septum and four sterigmata, 13–23 × 3–5 µm, basidioles dominant, similar in shape to basidia, but slightly smaller. Basidiospores ellipsoid, colorless, thin-walled, smooth, IKI+, CB–, (3.8–)4.4–5.3(–5.8) × (2.5–)3.2–3.9(–4.4) µm, L = 4.82 µm, W = 3.48 µm, Q = 1.35–1.39 (n = 60/2).

Additional material examined – China, Yunnan Province, Qujing, Qilin District, Cuishan Park, 25°54′ N, 103°69′ E; 1,875 m asl, on fallen angiosperm branch, 4 November, 2022, CLZhao 26028 (SWFC).

GenBank accession numbers – CLZhao 37038 ITS: PV940928, LSU: PX070092, rpb2: PX432797, rpb1: PX441306, tef1- α: PX439082; CLZhao 26028 ITS: PV940927.

Notes – Based on the multigene phylogeny ( Figs 1, 3), Gloeocystidiellum membranaceum clustered together with G. bisporum, G. clavuligerum (Höhn. & Litsch.) Nakasone, G. kenyense Hjortstam, and G. porosellum. However, morphologically, G. bisporum differs from G. membranaceum by having basidia with two sterigmata, oval to subglobose basidiospores ^{[ 152]} ; G. clavuligerum differs by its cream to ochraceous hymenophore, generative hyphae with clamp connections (Nakasone 1982); G. kenyense has larger fusiform cystidia (20–100 × 8–18 µm), and subcylindrical basidia ^{[ 153]} ; G. porosellum has pale cream coloured, smooth basidiomata, thin-walled, subfusiform cystidia, constricted basidia ^{[ 154]} .

Gloeocystidiellum punctatum Y.L. Deng & C.L. Zhao, sp. nov. Figure 11

Index Fungorum number: IF852412

Figure 11. 

Basidiomata and microscopic structures of Gloeocystidiellum punctatum (holotype). (a) Basidiomata on the substrate. (b) Section of hymenophore. (c) Basidiospores. (d) Basidioles. (e) Basidia. (f) Section of hymenium. Scale bars: (a) = 1 cm, (b) = 1 mm, (c) = 5 µm, (d)–(f) = 10 µm.

Diagnosis – Differs from other species in the genus by grandinioid, white to cream hymenial surface, thin-walled generative hyphae with clamp connections, and thin-walled ellipsoid basidiospores.

Etymology – referring to the punctate basidiomata.

Type – China, Yunnan Province, Zhaotong, Qiaojia County, Yaoshan Town, Yaoshan National Nature Reserve, 27°08′ N, 103°09′ E, 2,220 m asl, on fallen angiosperm branch, leg. C.L. Zhao, 23 August, 2020, CLZhao 20755 (SWFC).

Description – Basidiomata annual, resupinate, closely adnate, ceraceous, up to 6 cm long, 1.9 cm wide, and 0.2 mm thick. Hymenial surface grandinioid, white to cream when fresh, cream upon drying. Sterile margin thin, slightly cream, up to 1 mm.

Hyphal system monomitic, generative hyphae with clamp connections, colorless, thin-walled, branched, 1.5–3.8 µm in diameter, IKI–, CB–; tissues unchanged in KOH. Gloeocystidia abundant, tubular, basally inflated and slightly tapering towards the apices, thick-walled, thinning towards apex, 51.5–106 µm long, 8.5–15 µm wide, the protoplasmic content granular and yellowish in KOH. Basidia subclavate, colorless, thin-walled, with a basal clamp connection and four sterigmata, 16–24 × 3.5–5 µm, basidioles dominant, similar shape to basidia, but slightly smaller. Basidiospores ellipsoid, colorless, thin-walled, verruculose, IKI+, CB–, 4–6.5 × 2.5–4.5 µm, L = 5.03 µm, W = 3.64 µm, Q = 1.3–1.47 (n = 60/2).

Additional material examined – China, Yunnan Province, Zhaotong, Qiaojia County, Yaoshan Town, Yaoshan National Nature Reserve, 27°08′ N, 103°09′ E, 2,220 m asl, on fallen angiosperm branch, leg. C.L. Zhao, 23 August, 2020, CLZhao 20657 and CLZhao 20907 (SWFC); Yiliang County, Luozehe Town, Li Jiaping Village, 27°49′ N, 103°91′ E, 1,700 m asl, on dead bamboo, leg. C.L. Zhao, 25 August, 2022, CLZhao 23890 (SWFC); Qujing City, Qilin District, Cuishan, 25°54′ N, 103°69′ E, 1,500 m asl, on fallen angiosperm branch, leg. C.L. Zhao, 6 November, 2022, CLZhao 26935 (SWFC); Zhaotong, Wumeng Mountain National Nature Reserve, 27°32′ N, 103°72′ E, 2,500 m asl, on fallen angiosperm branch, leg. C.L. Zhao, 2 September, 2023, CLZhao 33627 (SWFC); Dehong, Yingjiang County, Tongbiguan Provincial Nature Reserve, 24°71′ N, 97°94′ E, 1,500 m asl, on fallen angiosperm branch, leg. C.L. Zhao, 21 July, 2023, CLZhao 30863, and CLZhao 30864 (SWFC); Diqing, Weixi County, Weideng Town, Fuchuan Village, 27°10′ N, 99°16′ E, 2,000 m asl, on fallen angiosperm branch, leg. C.L. Zhao, 12 October, 2023, CLZhao 34197 (SWFC); Dehong, Mang City, Mengjia Town, Sanxian Cave Park, 24°38′ N, 98°62′ E, 1,370 m asl, on fallen angiosperm branch, leg. C.L. Zhao, 30 June, 2024, CLZhao 37129 (SWFC); Tengchong, Tuantian Town, Gaoligong Mountain National Nature Reserve, 25°55′ N, 98°58′ E., 2,600 m asl, on fallen angiosperm branch, 7 July, 2024, CLZhao 39107, CLZhao 39124, CLZhao 39155, and CLZhao 39158 (SWFC).

GenBank accession numbers – CLZhao 20755 ITS: PP356586, LSU: PP785346, mtSSU: PV774693; CLZhao 20907 ITS: PP356587, LSU: PP785347, mtSSU: PV774694; CLZhao 23890 ITS: PV771056, LSU: PV771607, mtSSU: PV774695; CLZhao 26935 ITS: PV771057; CLZhao 33627 ITS: PP356588; CLZhao 30863 ITS: PV771058, LSU: PP785348, mtSSU: PV774696; CLZhao 30864 ITS: PV771059, LSU: PP785349, mtSSU: PV774697; CLZhao 34197 ITS: PV771060; CLZhao 37129 ITS: PV771061, LSU: PV771608, mtSSU: PV774698; CLZhao 39107 ITS: PV771062, LSU: PV771609, mtSSU: PV774699; CLZhao 39124 ITS: PV771063, LSU: PV771610, mtSSU: PV774700; CLZhao 39155 ITS: PV771064, LSU: PV771611, mtSSU: PV774701; CLZhao 39158 ITS: PV771065, LSU: PV771612, mtSSU: PV774702.

Notes – The phylogram ( Fig. 3) revealed that Gloeocystidiellum punctatum is nested within the Gloeocystidiellum clade, as a sister to G. porosum. However, morphologically, G. porosum has yellowish to isabelline, smooth hymenophore, thin- to slightly thick-walled, tubular to sinuous gloeocystidia (80–150 × 8–15 µm), and subcylindrical to ellipsoid basidiospores (5–6 × 2.5–3 µm). Morphologically, G. kenyense, G. lojanense A. Jaram., D. Cruz & Decock and G. yunnanense Y.L. Zhao & C.L. Zhao are similar to G. punctatum. However, G. kenyense differs in its cream to ochraceous basidiomata, smaller gloeocystidia (35–85 × 7–16 µm), and longer cylindrical basidia (21–27 × 4–5 µm) ^{[ 149]} ; G. lojanense can be distinguished by its bright grayish white and slightly light yellow hymenial surface, thin- to thick-walled generative hyphae, smaller gloeocystidia (80–90 × 7–8 µm), larger basidia (25–35 × 5–6 µm), and longer basidiospores (6.5–8 µm × 3.4–4.5 µm) ^{[ 149]} ; G. yunnanense is distinct by having smaller clavate (25–48.2 × 6.4–9.6 µm) and tubular (22.6–47.2 × 4.1–9.5 µm) gloeocystidia, basidia (12.5–14.5 × 3.5–4.5 µm), and basidiospores (3.9–4.7 × 3–3.5 µm) ^{[ 150]} .

Note 25 Family Gloeodontiaceae Y.L. Deng & C.L. Zhao, fam. nov.

Index Fungorum number: IF 861348

Type genus – Gloeodontia Boidin

Etymology – referring to the type genus Gloeodontia.

Description – Basidiomata resupinate or effused-reflexed, ceraceous to membranous consistency. Hymenophore smooth to odontioid. Hyphal system monomitic; generative hyphae with clamp connections. Cystidia present, Basidia cylindrical to urniform with four sterigmata, thin to thick-walled. Basidiospores ellipsoid to globose, asperulate, acyanophilous, and amyloid.

Notes – Gloeodontia was created by Boidin ^{[ 155]} and could not be assigned to any recognized family of Russulales, and it was treated as incertae sedis. Recent research have reported some new species based on morphology and phylogenetic analyses. However, phylogenetic tree analysis indicated that Gloeodontia formed a separate clade, and it was not placed in any recognized family of Russulales ^{[ 30, 82]} . In this study, based on combined ITS, nLSU, mtSSU, rpb2, and tef1- α data of Russulales, the phylogenetic analyses and divergence time ( Figs 1, 2) also showed that Gloeodontia could not be assigned to any recognized family. The divergence time of the Gloeodontia clade occurred in 178.7 Mya with a 95% highest posterior density (HPD) of 139.36–218.13 Mya. Thus, the genus is placed into the new family Gloeodontiaceae.

Note 26 Gloeodontia Boidin

Index Fungorum number: IF17666

Type species – Gloeodontia discolor (Berk. & M.A. Curtis) Boidin

Notes – Gloeodontia Boidin was typified by G. discolor (Berk. & M.A. Curtis) Boidin ^{[ 155]} , and characterized by a combination of resupinate or effused-reflexed basidiomata of ceraceous to membranous consistency, smooth to odontioid hymenophore, a monomitic or dimitic hyphal system, clamped hyphae, presence of cystidia, cylindrical to urniform basidia, and colorless to pale yellow, thick-walled, asperulate, ellipsoid to globose, acyanophilous and amyloid basidiospores ^{[ 155]} . Phylogenetic relationships of russuloid basidiomycetes with an emphasis on non-gilled taxa revealed that four species of Gloeodontia formed a monophyletic clade that grouped with Russulales and Stereales clades ^{[ 26, 30, 84]} , and additionally, a new combination G. subasperispora was proposed ^{[ 26]} . Leal-Dutra et al. ^{[ 84]} studied Lachnocladiaceae and Peniophoraceae (Russulales) and showed that Gloeodontia formed a single clade and then grouped with the clades, Amylostereaceae, Auriscalpiaceae, Bondarzewiaceae, Gloeocystidiellum, Russulaceae, and Stereaceae. Nine species have been accepted in the genus ^{[ 26, 30, 84]} . In this study, a new species G. sinensis is proposed based on ITS + nLSU + mtSSU + rpb2 + tef1- α and ITS + nLSU data ( Figs 1, 6), and morphological characteristics ( Figs 12, 13).

Gloeodontia sinensis Y.L. Deng & C.L. Zhao, sp. nov. Figures 12, 13

Index Fungorum number: IF860766

Figure 12. 

Basidiomata and microscopic structures of Gloeodontia sinensis (holotype). (a) Basidiomata on the substrate. (b) Characteristics of hymenophore. (c) Basidiospores. (d) Basidioles. (e) Basidia. (f) Cystidia. (g) Section of the hymenium. Scale bars: (a) = 1 cm, (b) = 1 mm, (c) = 5 μm, (d)–(g) = 10 μm.

Figure 13. 

Sections of hymenium of Gloeodontia sinensis (holotype). (a)–(c) Basidiospores. (d)–(f) Basidia and basidioles. (g)–(i) Cystidia. Scale bars: (a)–(i) = 10 µm.

Diagnosis – Differs from other species by the coriaceous basidiomata with white to cream hymenial surface odontoid, a monomitic hyphal system with clamped generative hyphae, and ellipsoid, verrucose basidiospores (3.4–4.5 × 2.4–3.4 µm).

Etymology – referring to the locality (China) of the type specimen.

Type – China, Yunnan Province, Diqing, Weixi County, Weideng Town, Fuchuan village, 27°09′ N, 99°17′ E, 1,910 m asl, on fallen angiosperm branch, leg. C.L. Zhao, 12 October, 2023, CLZhao 34280 (SWFC).

Description – Basidiomata annual, resupinate, closely adnate, coriaceous, without odor or taste when fresh, up to 8 cm long, 2 cm wide, and 150 μm thick. Hymenial surface odontoid, thin, white to cream when fresh, cream to buff upon drying. Sterile margin white, up to 1 mm.

Hyphal system monomitic; generative hyphae with clamp connections, colorless, thin-walled, smooth, moderately branched, 2–3 µm in diameter, IKI–, CB–; tissues unchanged in KOH. Cystidia cylindrical with a mastoid at the tip, 10–15 × 4–5 µm. Basidia cylindrical, with a basal clamp connection and four sterigmata, 11–18 × 3–4 µm; basidioles numerous, in shape similar to basidia but smaller. Basidiospores ellipsoid, colorless, thin-walled, verrucose, amyloid, CB–, (3.3–)3.4–4.5(–4.8) × (2.3–)2.4–3.4(–3.7) µm, L = 3.98 µm, W = 2.87 µm, Q = 1.38–1.39 (n = 60/2).

Additional material examined – China, Yunnan Province, Diqing, Weixi County, Zhonglu Town, Lagaluo village, 27°15′ N, 99°15′ E, 3100 m asl, on fallen angiosperm branch, leg. C.L. Zhao, 14 October, 2023, CLZhao 34748 (SWFC).

GenBank accession numbers – CLZhao 34280 ITS: PV147170, LSU: PV185856, mtSSU: PV283189, rpb1: PX441307; CLZhao 34748 ITS: PV147171, LSU: PV185857, mtSSU: PV399821, tef1- α: PV400175.

Notes – The phylogenetic analyses ( Figs 1, 6) revealed that Gloeodontia sinensis clustered within the genus Gloeodontia, and is closely related to G. columbiensis and G. subasperispora. However, G. columbiensis differs from G. sinensis by having thick-walled, cylindrical cystidia, both larger thin-walled, vesicular to cylindrical gloeocystidia (20–60 × 5–8 µm), clavate basidia (15–35 × 5–6 µm), and ellipsoid basidiospores (5.5–7 × 3.5–4.5 µm) ^{[ 156]} ; G. subasperispora can be distinguished from G. sinensis by its greyish-white to pale ochraceous, smooth hymenial surface, longer yellowish gloeocystidia (20–30 × 3–5 µm) ^{[ 26]} . Morphologically, G. sinensis is reminiscent of G. yunnanensis C.L. Zhao by thin-walled generative hyphae with clamp connections, sharing asperulate basidiospores. However, G. yunnanensis has cream to buff to brownish vinaceous smooth hymenial surface, larger obclavate gloeocystidia (32–57 × 6–9 µm), and thick-walled, subglobose to globose basidiospores measuring 3.3–4.3 × 2.5–3.5 µm ^{[ 82]} .

Family Hericiaceae Donk 1964

Index Fungorum number: IF80854

Type genus – Hericium Pers.

Notes – Hericiaceae is characterized by annual, resupinate, effused-reflexed, pileate-sessile to flabelliform basidiomata, smooth, poroid to hydnoid hymenophore, monomitic or dimitic hyphal system, generative hyphae with clamp-connections, inamyloid or amyloid, skeletal hyphae inamyloid or dextrinoid ( Pseudowrightoporia, Wrightoporiopsis), gloeoplerous hyphae and gloeocystidia present or absent, with asperulate, spinulose or echinulate, hyaline, amyloid basidiospores. The members of this family include wood decaying fungi ^{[ 1]} .

Note 27 Dentipellicula Y.C. Dai & L.W. Zhou

Index Fungorum number: IF564153

Type species – Dentipellicula taiwaniana (Sheng H. Wu) Y.C. Dai & L.W. Zhou

Notes – Dentipellicula was segregated from Dentipellis and proposed for two hydnoid fungal species, Dentipellis leptodon (Mont.) Maas Geest. and Dentipellis taiwaniana Y.C. Dai, G.M. Gates, X.H. Ji & P. Du which were transferred to the genus Dentipellicula with the latter designated as the generic type. Dentipellicula is characterized by its annual, effused-reflexed to pileate basidiomata, hydnoid hymenophore, soft corky, cream to ivory yellow to buff to cinnamon-buff spines, a monomitic hyphal system; generative hyphae with clamp connections, slightly thick-walled, minutely rough basidiospores ^{[ 30]} . Chen et al. ^{[ 157]} proposed D. austroafricana Jia J. Chen, L.L. Shen & Y.C. Dai, which was recognized in the Dentipellicula clade and distant from Dentipellis based on combined ITS and nLSU sequences. Another species, D. guyanensis Yuan Yuan, M. Zhou, Jia J. Chen & Vlasák shares several morphological characteristics with other Dentipellicula species, such as an annual growth habit, a monomitic hyphal system with non-amyloid, non-dextrinoid and acyanophilous generative hyphae ^{[ 30, 158]} .

Note 28 Dentipellis Donk

Index Fungorum number: IF17487

Type species – Dentipellis fragilis (Pers.) Donk

Notes – Dentipellis was typified by D. fragilis. This genus was introduced to accommodate the species characterized by an annual growth habit, hydnoid basidiomata, soft spines, a monomitic hyphal structure with clamp connections and cyanophilous hyphae, and amyloid rough basidiospores ^{[ 30, 159]} . Zhou & Dai ^{[ 30]} demonstrated that Dentipellis was polyphyletic and segregated D. leptodon (Mont.) Maas Geest. and D. taiwaniana Sheng H. Wu from Dentipellis based on ITS and nLSU rDNA sequences. Chen et al. ^{[ 11]} maintained that Dentipellis remained polyphyletic based on ITS and nLSU rDNA sequences, therefore, a broad concept for Dentipellis s.l. was adopted ^{[ 160]} . Recently, based on molecular and morphological analyses, more new taxa were described in Dentipellis sensu lato ^{[ 157, 160, 161]} . All Dentipellis spp. were found from the northern hemisphere ^{[ 120, 157, 160, 161]} . In the present study, a new species D. yingjiangensis is described based on morphological and molecular systematics analysis inferred from ITS + nLSU data ( Fig. 4).