Two new species of Phaeoclavulina (Gomphaceae, Gompales, Basidiomycota) from Hunan Province, China are distinguished on the basis of the morphological characters and molecular phylogenetic analyses. Phaeoclavulina aeruginea is characterized by basidiomata ramarioid, repeatedly branched, stipe yellowish brown, copper-green and blunt branch tips, and the context, turning wine red when bruised or exposed. Phaeoclavulina cinnamomea produces the cinnamon basidiomata, crowded branches, and large basidiospores with truncate (volcanic) spines, which is particularly rare in Phaeoclavulina. The two species are illustrated by drawings and photographs, including scanning electron micrographs. Their taxonomic distinctness was supported by the phylogenetic analyses of internal transcribed spacer (ITS) and nuclear ribosomal large subunit (nrLSU) sequence data. The ITS and nrLSU sequences newly generated in this study were deposited in GenBank. A key to Phaeoclavulina species in China is provided.

Two new species of Trechispora indigenous to southern China, T. laxa and T. tongdaoensis, are described and illustrated, and the first record of T. khokpasiensis in China is reported. Molecular phylogenetic analyses of the concatenated nuclear rDNA ITS1–5.8S–ITS2 and nuclear large subunit sequences supported the inclusion of the three species within the Trechispora clade, together with species formerly classified in Scytinopogon. The new species are similar in micromorphology to species of Trechispora (as traditionally circumscribed) but are distinguished by having coralloid basidiomata. A key to the known coralloid Trechispora species in China is provided.

Specimens of Clavulinopsis (Clavariaceae, Agaricales) collected in China were studied using morphological and molecular methods. Six species—C. aspersa, C. bicolor, C. bispora, C. erubescens, C. incarnata, and C. tropicalis—are described as new to science, and C. trigonospora is a newly recorded species in China. Phylogenetic analysis was conducted based on a combined dataset of internal transcribed spacer and nuclear ribosomal RNA large subunit sequences. The phylogenetic reconstruction revealed that the six new species each formed an independent lineage, and the samples of C. trigonospora from China were nested with accessions of C. trigonospora collected from Italy. The morphology of the seven Chinese species is described in detail, and is illustrated with line drawings and photographs. A key to the known Clavulinopsis species in China is provided.

Based on morphological and molecular evidence, 12 specimens have been identified as belonging to three previously unrecognized species of Clavaria, which are here described as C. divergens, C. orientalis, and C. tongdaoensis. Clavaria divergens is characterized by its branched, white basidiomata. Clavaria orientalis and C. tongdaoensis are very similar to C. zollingeri in the field. However, C. orientalis is distinguished by its more robust branches, while C. tongdaoensis differs by its varied or paler color of basidiomata. A concatenated sequence dataset (ITS-nrLSU-RPB2) was used for multi-locus phylogenetic analysis. The phylogenetic tree of Clavaria showed that the three branched species each formed a distinct lineage with strong support. A key to the known branched species of Clavaria in China is provided.

Introduction: Plant mitochondrial genomes (mitogenomes) are known for their structural complexity, particularly within the Orchidaceae. To understand the evolutionary dynamics in the endangered genus Calanthe , this study provides the first complete mitogenome assembly for the endangered species Calanthe sieboldii , a species of horticultural and conservation importance. Methods: A hybrid sequencing approach combining Nanopore long reads and BGI short reads was used for denovo assembly. The genome was annotated, and we performed comparative analyses of repetitive sequences, interorganellar DNA transfer, codon usage, RNA editing, synteny, and phylogeny. Results: The 644,236 bp mitogenome exhibits a highly fragmented architecture, comprising 21 independent circular chromosomes ranging from 19.9 to 48.7 kb. We annotated 39 unique protein-coding genes, 23 tRNA genes, and 3 rRNA genes. The genome is characterized by a high density of repetitive sequences and a massive influx of chloroplast DNA, with mitochondrial–plastid sequences accounting for 12.72% of the total length. Comparative synteny analysis with other orchid species revealed an almost complete loss of gene order, highlighting extreme structural rearrangement. Despite this plasticity, core molecular features, such as codon usage and predicted RNA editing patterns, remain conserved. Phylogenetic analysis robustly placed C. sieboldii within the Orchidaceae. Discussion: This study decodes a complex multichromosomal mitogenome, reinforcing the paradigm of dynamic structural evolution in orchids and providing a vital genomic resource to support conservation efforts and evolutionary research on the Calanthe genus.