Morphological Evidence Research Articles

Morphological and molecular evidence reveals three new species of Gelidium (Gelidiaceae, Rhodophyta) for the southern Mexican Tropical Pacific

Abstract The genus Gelidium is a representative element of the Mexican Tropical Pacific. The recent use of molecular tools has allowed us to resolve the taxonomic problems of some species and to increase the knowledge regarding this group of red algae in the region. The present study aimed to evaluate specimens collected in the southern Mexican Tropical Pacific using molecular markers and morphological characters. Samples were collected from four locations along the coast of Oaxaca state. They were characterised morphologically and molecularly using rbcL and COI–5P. Phylogenetic analysis classified the examined specimens into three independent clades, representing taxonomic entities different from what has been described previously for the genus. With the support of morphological data and genetic distances, we propose three new species for the Mexican Tropical Pacific: Gelidium dawsonii sp. nov., Gelidium longisporophyllum sp. nov., and Gelidium rubruparvum sp. nov. Some of the distinct characteristics of these species are based on little size of G. rubruparvum, the branching pattern of G. longisporophyllum and G. dawsonii, the number of layers of medullary cells in G. dawsonii and G. rubruparvum, and the tetrasporangial sorus in G. longisporophyllum. We also highlight the relationship between Asian and Mexican species and the value of using different tools in the evaluation of the taxonomic status of the genus Gelidium.

Identification of two new species of Mecistocephalus (Chilopoda, Geophilomorpha, Mecistocephalidae) from southern China and the re-description of Mecistocephalus smithii Pocock, 1895

Mecistocephalus Newport, 1843 is the most diverse genus in the family Mecistocephalidae; however, only two species have been recorded in mainland China to date. Therefore, taxonomic research on Chinese Mecistocephalus needs further research. In this study, the species diversity of Mecistocephalus in southern China was investigated using the mitochondrial marker COI integrated with morphological evidence. Species delimitation using Automatic Barcode Gap Discovery, Poisson Tree Processes, and phylogenetic and morphological analyses revealed ten species, including two newly described species, M. chuensis Jiang & You, sp. nov. and M. huangi Jiang & You, sp. nov. Furthermore, based on newly collected specimens, the presence of the little-known species M. smithii Pocock, 1895 was confirmed in China and thoroughly re-described.

Revalidation of Enteromius crocodilensis (Fowler, 1934) from synonymy with the disjunctly distributed Enteromius argenteus (Günther, 1868) based on molecular and morphological evidence.

The rosefin barb, Enteromius argenteus, as currently described, is a freshwater fish with a distribution that is geographically separated and divided into the northern population in the Kwanza River system in Angola, and the southern population in the Inkomati River system in South Africa and Eswatini. Due to this disjunct distribution pattern, it is likely that the two populations represent distinct species. mtDNA sequence data and detailed examination of morphometric characters revealed considerable genetic (2.8%-3.5%) and morphological differentiation of the two populations, suggesting their recognition as two distinct species. Enteromius crocodilensis is revalidated and redescribed for the southern population that is readily distinguished from E. argenteus by nonoverlapping circumpeduncular scale counts (12-13 vs. 14) and color pattern (presence of a conspicuous dark band along the midline vs. absence of characteristic melanin patterns). Phylogenetic analysis based on mtDNA cytochrome oxidase subunit I (COI) data places both E. argenteus and E. crocodilensis in a well-supported clade that includes a number of morphologically similar sawfin barb species from southern and central Africa.

An integrative approach to the taxonomy of Oxymycterus paramensis (Rodentia, Cricetidae) and related nominal forms

Abstract Oxymycterus includes 17 species of small- to medium-sized sigmodontine rodents. The taxonomy of this genus has been widely studied, but several unresolved issues persist. One example of this is the Paramo Hocicudo, Oxymycterus paramensis, which over its extended latitudinal range has been associated with several nominal forms that have not been evaluated with an integrative approach. Based on phylogenetic analyses of the Cytb gene, qualitative and quantitative morphological characters, and environmental niche modeling, we reexamined the taxonomic status of the nominal forms akodontius, jacentior, and paramensis while considering the recently recognized species O. willkaurco. The phylogenetic reconstruction guided subsequent analysis of morphological variation and the development of the niche models. Considering the results in an integrative framework, we observed congruence among phylogenetic, species distribution models, and environmental niche models (a proxy indicating different environmental preferences), which support the recognition of 2 species within the concept of O. paramensis s.l. At the same time, we did not observe congruent support for this taxonomic hypothesis from morphological evidence, with the absence of diagnostic qualitative or quantitative characters differentiating the 2 taxa. Considering that some lines of evidence suggest the interruption of gene flow, we see more support for recognizing existing names for 2 taxa at the species level: O. paramensis, endemic to Bolivia; and O. akodontius (which has priority over jacentior), distributed from southern Bolivia to northwestern Argentina. However, we recommend more detailed studies to test the taxonomic scenario advanced here.

Correction: Giunta et al. Ameliorative Effects of PACAP against Cartilage Degeneration. Morphological, Immunohistochemical and Biochemical Evidence from in Vivo and in Vitro Models of Rat Osteoarthritis. Int. J. Mol. Sci. 2015, 16, 5922–5944

In the original publication [...]

PATH-19. DIAGNOSTIC UTILITY OF MOLECULAR PROFILING IN ADULT DIFFUSE GLIOMA

Abstract INTRODUCTION With the publication of World Health Organization Classification of the Central Nervous System Tumors (WHO CNS5), molecular profiling has become essential for the diagnosis of CNS tumors. To test for the diagnostic molecular alterations, we developed a targeted DNA sequencing panel (Nakashima et al. 2024) to analyze 113 genes, chromosomal abnormalities, and MGMT promoter methylation. This study aimed to evaluate our diagnostic approach using the targeted sequencing panel. PATIENTS AND METHODS We included 72 cases of diffuse adult gliomas diagnosed at our institute between June 2023 and May 2024. We analyzed the tumor diagnoses based on the pathological and immunohistochemical findings as well as the targeted sequencing panel findings. RESULTS The tumor diagnoses were as follows: glioblastoma, IDH-wildtype: 32 cases, astrocytoma, IDH-mutant: 17 cases, oligodendroglioma, IDH-mutant and 1p/19q-codeleted: 15 cases, others: 8 cases. Among 32 cases of IDH1/2 mutations, 28 cases (87.5%) with IDH1 R132H mutation were diagnosed by immunohistochemistry using anti-IDH1 R132H antibody, whereas 4 (12.5%) (3 with IDH2 mutation, and 1 with IDH1 R132S) were diagnosed by the targeted sequencing panel. Of the 32 glioblastoma cases, 6 (18.8%) did not show necrosis or microvascular proliferation and were diagnosed based on either TERT promoter mutation, EGFR amplification, or chromosome 7/chromosome 10 abnormalities. Moreover, 24 out of 26 resected cases (92.3%) were diagnosed morphologically, whereas 4 of 6 biopsy cases (66.7%) were diagnosed molecularly (p=0.0056). Among the 17 cases of astrocytoma, IDH-mutant, 2 (11.8%) showed homozygous deletion of CDKN2A/B. There were 4 cases (5.6%) out of 72 that did not satisfy the diagnostic criteria for glioblastoma, astrocytoma, oligodendroglioma. CONCLUSION Approximately 95% of cases were diagnosed based on WHO CNS5 criteria with molecular profiling. We also demonstrate molecular profiling is useful in glioblastoma diagnostics, especially in biopsy cases where morphological diagnostic evidence is not recognized.

Catalogue of fungi in China 4: Didymiaceae and Physaraceae (Myxomycetes)

ABSTRACT Myxomycetes play crucial ecological roles, yet their species diversity, distribution, and taxonomic relationships remain poorly understood. In this study, we examined 104 specimens from 19 provinces in China. Through morphological analysis, we identified a group of species with reduced lime formation, a feature typically associated with the Physaraceae, but with key morphological similarities to the Diderma. A comprehensive phylogenetic analysis was conducted using three genes (nSSU, EF-1α, and COI), resulting in a dataset of 452 sequences from 116 species. Notably, we identified a distinct clade within Didymiaceae containing species with fewer lime knots, a trait traditionally linked to Physaraceae. This clade, designated as the new genus Neodiderma, was phylogenetically positioned as a sister group to Diderma, potentially representing a transitional group between Didymiaceae and Physaraceae, supported by both morphological and molecular evidence. Eleven new species — N. macrosporum, N. pseudobisporum, N. verrucocapillitium, N. rigidocapillitium, N. rufum, Physarum guangxiense, P. subviride, P. nigritum, P. biyangense, P. neoovoideum, and P. jilinense — were identified from China, and their phylogenetic positions were analysed. Additionally, N. spumarioides (formerly Diderma spumarioides) was recombined. The new and recombined species were formally described and illustrated, and a key to the sections and species of Neodiderma and Physarum was provided.

Morphology, phylogeny, and mitogenomics reveal a new entomopathogenic fungus, Blackwellomyces changningensis (Hypocreales, Clavicipitaceae), from southwestern China

ABSTRACT Two species of Blackwellomyces (Clavicipitaceae, Hypocreales, Ascomycota) were discovered during an investigation of the diversity of entomopathogenic fungi. A new fungus and one known fungal species that were gathered from Yunnan Province were described in this study. Blackwellomyces changningensis, sp. nov. was described using morphology and phylogenetic evidence from 14 mitochondrial protein-coding gene (PCG) data sets (atp6, atp8, atp9, cob, cox1, cox2, cox3, nad1, nad2, nad3, nad4, nad5, nad6, and nad4L) and six nuclear genes (ITS [ITS4 and ITS5], 18S nuc rDNA [18S], 28S nuc rDNA [28S], tef1-α, rpb1, and rpb2). B. changningensis were found parasitic to Lepidoptera larvae and to produce filiform ascospores with septations. The asexual conidia were ovoid to ellipsoid in shape. Phylogenetic analysis and morphological observations concurred that the fungus belonged to a different species within the genus of Blackwellomyces. The foundation for further taxonomic, genetic, and evolutionary biological studies of the genus Blackwellomyces was laid by this work.

Morphological, molecular and 3D synchrotron X-ray tomographic characterizations of Helicascus satunensis sp. nov., a novel mangrove fungus.

A new species of Helicascus satunensis sp. nov. was collected on mature dead fruits of the Nypa palm in Satun Province, southern Thailand. Its morphological characteristics are similar to those of the genus Helicascus. Recently, a genus Helicascus with three species from marine habitats worldwide was studied. The morphology of this fungus was investigated and combined with multigene sequence analyzes of small subunit (SSU), large subunit (LSU), internal transcribed spacer (ITS) ribosomal DNA, translation elongation factor 1-alpha (TEF-1α) and RNA polymerase II (RPB2) genes. Morphologically, H. satunensis sp. nov. is characterized by semi-immersed, lenticular ascomata, multilocules, a bitunicate ascus and smooth, obovoid, dark brown ascospores that are one-septate and unequally two-celled. In addition, 3D visualization using synchrotron X-ray tomography was performed to investigate the interaction between fruiting body and substrata. Molecular phylogeny with multigene revealed that H. satunensis sp. nov. belongs to the family Morosphaeriaceae, order Pleosporales, class Dothideomycetes. Furthermore, H. satunensis sp. nov. forms a well-supported clade with Helicascus species described from marine habitats. Based on the unique morphological and molecular evidence, we propose this fungus, H. satunensis sp. nov., as a new species for Helicascus.

Mallotus bullatus (Euphorbiaceae), a new species from Southwest China based on morphological characters and phylogenetic evidence

Mallotus bullatus M.T.An & J.H.Yu, sp. nov. (Euphorbiaceae), a species new to science discovered in Guizhou, China, is described and illustrated here, and its phylogenetic position among other Mallotus species is presented. Morphological, micro-morphological, and molecular evidence is presented as attestation of its novelty. The new species morphologically resembles M. philippensis var. reticulatus and M. philippensis var. philippensis, but it clearly differs by having bullate leaf surfaces (vs. not bullate), leaf margins entire or nearly so (vs. entire or nearly so in M. philippensis var. philippensis and coarsely serrate in M. philippensis var. reticulatus), leaf margins sometimes bearing red glands (vs. red glands absent), 5 sepals in staminate flowers (vs. 3–4 in M. philippensis var. philippensis and 4 in M. philippensis var. reticulatus), fruits with spines (vs. spines absent in M. philippensis var. philippensis and present in M. philippensis var. reticulatus), and abaxial leaf epidermal scattered and clustered vein hairs 0.1–0.8 mm long (vs. 0.04–0.28 mm long in M. philippensis var. philippensis and 0.05–0.1 mm long in M. philippensis var. reticulatus). Molecular phylogenetic analysis (BS = 100% / BS = 96%, PP = 1 / PP = 1) provides strong evidence supporting M. bullatus as a new species within the genus Mallotus and supports its placement in M. sect. Philippinenses as sister to M. philippensis.

Sarea cirrhendocarpa, a fungus species new to science from the southern Rocky Mountains

Sarea cirrhendocarpa, a resinicolous fungus, is here described as new to science from two specimens collected in the Indian Peaks Wilderness (Arapaho-Roosevelt National Forest, Colorado, USA) during the summer of 2023, a third specimen from Holy Cross Wilderness (White River National Forest, Colorado, USA) during the summer of 2024, and a fourth specimen from the Kachina Peaks Wilderness (Coconino National Forest, Arizona, USA) that was collected in 1998. The new species is readily distinguished from its closest relative, Sarea resinae, by its larger apothecia, smaller asci, smaller ascospores, and burnt orange hymenium (bicolored towards uppermost portions) among other traits. A phylogeny derived from the nuclear ribosomal internal transcribed spacer (ITS) region suggests that S. cirrhendocarpa is sister to and genetically distinct specimens of Sarea resinae sampled from around the world including North America. These molecular results in combination with the clear morphological differences lead us to propose this as a new species so far only known from the southern Rocky Mountains of North America. This new taxon is placed for the time being within the genus Sarea owing to inconclusive phylogenetic and morphological evidence that would support generic separation within the Sareomycetes. The name Sarea resinae is retained and new combinations for S. klamathica and S. lignicola are provided.

High-resolution HI mapping of nearby extremely metal-poor blue compact dwarf galaxies

Optical observations of blue compact dwarf galaxies (BCDs) show they typically have high specific star formation rates black (sSFRs) and low metallicites. A subset of these galaxies (those with the lowest gas phase metallicities) display cometary optical morphologies similar to those found at high redshift. Whether this combination of properties predominantly arises from interactions with neighbours or via accretion from the cosmic web, or is indeed due to something else, remains unclear. Our aim is to use high-resolution mapping to gain insights into the processes driving the observed properties of a sample of extremely metal-poor (XMP) BCDs. We present Very Large Array B-- and C--configuration mapping of the four BCDs of our sample. For three of the targeted BCDs, we also detected and mapped the in their nearby companions. In these three cases, there is morphological and kinematic evidence of a recent flyby interaction between the BCD and a nearby companion galaxy. The evidence for recent interactions for these three BCDs is corroborated by our analysis of the tidal forces exerted on the BCDs by companions with available spectroscopic redshifts. In one of these cases, J0204--1009, we obtain sufficient spatial resolution to determine that the BCD is dominated by dark matter black (DM) and estimate its DM halo mass to be in the range of 1.2 times 1011 to 5.2 times 1011 However, it is the most isolated BCD in our small sample, J0301--0052, that shows one of the most asymmetric morphologies . J0301--0052 has a similar cometary morphology to its optical morphology, although the column density maximum is projected at the end of the optical tail. Our observations suggest that J0301--0052 may be undergoing a merger, while the other members of our BCD sample show evidence of a recent tidal interaction with a near neighbour. While our selection criteria favour BCDs with companions, our results are consistent with previous literature showing that most BCDs are associated with either mild tidal interactions or mergers.

Two new species and three new records of Diachea (Physarales) from China based on morphological and molecular evidence

Diachea is an important genus of myxomycetes, recognized for its ecological role and wide distribution. This study aimed to expand knowledge of species diversity within this genus in China. We collected Diachea specimens from various locations in Shaanxi and Sichuan provinces and characterized them through morphological analysis and phylogenetic analysis using four genetic markers: small subunit ribosomal RNA (nSSU), translation elongation factor 1-alpha (EF-1α), mitochondrial small subunit (mtSSU), and alpha-tubulin gene (α-Tub). Based on these analyses, we describe two new species, namely, Diachea plectophylla and D. sichuanensis, discovered in the Shaanxi and Sichuan provinces, respectively. Diachea plectophylla is distinguished by its dense, rigid capillitium, spore warts, and distinct separation of capillitium ends from the peridium. Diachea sichuanensis, closely related to D. leucopodia, is identified by its blunt-headed columella, clustered spore warts, and robust stalks. In addition to these new species, we recorded five previously documented species, including D. bulbillosa in Gansu province, D. leucopodia in Yunnan and Sichuan provinces, and D. subsessilis in Sichuan province. Detailed descriptions, micrographs, taxonomic comparisons, and an identification key are provided to aid in accurate identification. The discovery of these new species not only enhances the known diversity of slime molds in the region but also provides valuable information for future studies on their geographical distribution and ecological relationships.

Exploring frictional properties of upper plate fault reactivation in subduction zones: The Atacama Fault System in northern Chile

The Maule 2010 and Tohoku-Oki 2011 earthquakes demonstrated how dormant upper plate faults can be reactivated as normal faults by plate margin relaxation following megathrust slip. However, the reactivation mechanisms of these types of faults are yet unexplored. To provide a better understanding of these mechanisms, we collected fault core samples from fault segments of the Atacama Fault System in northern Chile. The sampled fault segments have clear morphological evidence of Quaternary reactivation as normal fault. We performed laboratory experiments to measure the fault strength, stability and dynamic weakening. We consider low-velocity tests for exploring the frictional strength and velocity dependence of friction via a double-direct shear apparatus and ii) high-velocity tests for investigating the frictional properties at seismic velocities via a rotary shear apparatus. The experiments revealed that fault cores have low frictional strength, velocity-strengthening behaviour and strong dynamic weakening. Additionally, a novel experimental procedure that simulates stress relaxation by stepwise reducing of the normal stress on the sample assembly showed: 1. Accelerating creep towards dynamic weakening in chlorite-rich gouges and 2. oscillatory sliding in fault gouges enriched in illite. By extrapolating our experimental observations to natural conditions, we conclude that stable sliding is favoured during the interseismic phase of the subduction earthquake cycle, whereas unstable sliding is favoured during the coseismic and postseismic phases. The latter occurs via normal stress reduction during the shift from interseismic compression to co- and postseismic tension at the plate margin.

A new species of Autocrates (Coleoptera: Trictenotomidae) revealed by DNA barcoding and morphological evidence

Autocrates soni sp. nov. is described from Vietnam based on morphological and molecular evidence. This beetle is characterised by reddish-brown pubescence on its ventral side and much shorter setae on its femora compared to the closely related species Autocrates vitalisi Vuillet, 1912. The validity of this new species is strongly supported by DNA barcode data from all known species of the genus Autocrates.

Phylogenetic and taxonomic revisions of Jurassic sea stars support a delayed evolutionary origin of the Asteriidae.

The superorder Forcipulatacea is a major clade of sea stars with approximately 400 extant species across three orders (Forcipulatida, Brisingida, Zorocallida). Over the past century, the systematics of Forcipulatacea have undergone multiple revisions by various authors, with some considering numerous families such as Asteriidae, Zoroasteridae, Pedicellasteridae, Stichasteridae, Heliasteridae, Labidiasteridae, and Neomorphasteridae, while others recognized only two families (i.e., Asteriidae and Zoroasteridae). Recent molecular analyses have shown the artificial nature of some of these groupings. Notably, four well-supported clades (Zorocallida, Brisingida, Stichasteridae, and Asteriidae) emerged from a synthesis of morphological and molecular evidence. The majority of extinct forcipulatacean species have been placed in modern families. However, many of these fossil species are in need of revision, especially those species placed within the Asteriidae, the largest of all forcipulatacean families. In light of recent advancements in forcipulatacean systematics, we comprehensively reassess six well-preserved Jurassic forcipulatacean taxa, including the earliest crown-group members from the Hettangian (∼201.4 Ma), and also describe two new Jurassic genera, Forbesasterias gen. nov. and Marbleaster gen. nov. We assembled the largest and most comprehensive phylogenetic matrix for this group, sampling 42 fossil and extant forcipulatacean species for 120 morphological characters. To infer phylogenetic relationships and construct an evolutionary timeline for the diversification of major clades, we conducted a Bayesian tip-dating analysis incorporating the fossilized birth-death process. A total of 13 fossil species were sampled in our analysis, including six taxonomically revaluated herein, two recently reappraised species from the Jurassic, and five additional species from the Cretaceous and Miocene. Contrary to prior assumptions, our results indicate that none of the Jurassic taxa investigated belong to Asteriidae or any other modern families, and instead represent stem-forcipulatids. Furthermore, our phylogenetic results suggest that Asteriidae likely originated during the late Cretaceous. Our findings highlight a greater early diversity within the Forcipulatacea than previously presumed, challenging existing perceptions of the evolutionary history of this significant clade of marine invertebrates.

Taxonomic notes on Sophora phulangkaensis, a new species of Sophora (Fabaceae – Sophoreae) from Thailand based on morphological and molecular evidence

Sophora phulangkaensis is illustrated and newly described here. The species shows similarities with its congener, S. exigua, by having an obovate terminal leaf let and up to 15 leaflets but differs in the floralparts. A morphological comparison between the two species is provided along with a discussion. The phylogenetic place- ment of then ewspecies is presented and discussed based on molecular evidence by nuclear (ITS) and chloroplast markers (matK). The results suggest that the new species is nested into sect. Rubriflorae, which includes S. exigua and S. huamotensis. The circumscription of sect. Rubriflorae is expanded after being redefined by our findings. In addition, the updated key to species of the genus Sophora for the Flora of Thailand is given based on recent specimen observations. Additionally, lectotypes for S. exigua, S. tonkinensis, and S. violacea var. pilosa are designated.

Too many spines, or an integrative foundation of the Echiniscus spinulosus morphogroup (Heterotardigrada: Echiniscidae)

AbstractHistorical taxonomic bias has started to be effectively removed in tardigrade taxonomy in the last two decades by the application of modern statistical, genetic and morphological tools. Many of the “old” tardigrade taxa have been redefined, and their succinct original diagnoses—refined, finally resulting in making them properly identifiable and less enigmatic. At the same time, many of the “old” species were synonymised and perished in the taxonomic wastebasket. Herein, we address the species distinction between Echiniscus spiniger Richters, 1904 and Echiniscus spinulosus (Doyère, 1840) by means of integrative analyses of 11 European populations collected in the Mediterranean, the Carpathians and the Baltic Sea islands of Öland and Gotland, covering the southern distribution zone and northernmost known localities within trustworthy geographic range of these species. We disclose that, as previously hypothesised, E. spiniger is conspecific with E. spinulosus, and synonymised accordingly. We deliver morphological evidence supporting the triphyly of the morphogroup, with all tropical and subtropical species truly lacking intracuticular pillars, whereas the Palaearctic lineage corresponding solely to E. spinulosus and Afrotropical lineage represented by E. belloporus Gąsiorek and Kristensen, 2018—occasionally exhibiting pillars in some specimens. A synopsis and key to all representatives of the E. spinulosus morphogroup are provided, pinpointing to some problems that must be taken into consideration during identification and solved in the future.

Four New Species of Deconica (Strophariaceae, Agaricales) from Subtropical Regions of China

Deconica is a relatively small genus, with only 90 names recorded in previous research. In this study, four new species of Deconica have been identified based on morphological and phylogenetic evidence from subtropical regions of China. This represents the first discovery of new species of Deconica in China. Morphologically, D. austrosinensis is characterized by medium-sized spores that are elliptical to elongated-ellipsoid in face view, and fusiform to sublageniform and slightly thick-walled pleurocystidia; D. furfuracea is identified by a well-developed and evanescent veil, medium-sized spores that are rhomboid to mitriform in face view, and fusiform to subclavate pleurocystidia that are rare and subacute at apex; D. fuscobrunnea is recognized by dark brown pileus, medium-sized spores that are rhomboid to mitriform in face view, an ixocutis pileipellis, lageniform cheilocystidia with a long neck and lacks pleurocystidia; D. ovispora is distinguished from other Deconica species by medium-sized spores that are ovoid in face view, an ixocutis pileipellis, lageniform cheilocystidia with a long to short neck, and lacks pleurocystidia. Their distinct taxonomic status is confirmed by the positions of the four new species in ITS + LSU phylogenetic trees. Detailed descriptions and morphological photographs of four new species are presented.

A new agaricoid species of Porotheleum (Porotheleaceae, Agaricales) from Shandong Province, China

Porotheleum microsporum, a new agaricoid species of the genus Porotheleum (Porotheleaceae, Agaricales), was found growing on the live bark of Salix babylonica in Quancheng Park (Ji’nan City, Shangdong Province, China). This discovery, a testament to our rigorous research, is described and illustrated based on morphological, molecular, and ecological evidence. Our phylogenetic analyses based on DNA sequences of the internal transcribed spacers 1 and 2 with the 5.8S rDNA (ITS) and the large subunit of nuclear ribosomal DNA (LSU) support the inclusion of this new species in the genus Porotheleum as it forms an independent clade in the phylogenetic tree. Morphologically, P. microsporum differs from any known species by combining a pale-yellow pileus with an ochre-yellow center and relatively small basidiospores.