Sexual reproduction is the basic way to form high genetic diversity and it is beneficial in evolution and speciation of fungi. The global diversity of teleomorphic species in Ascomycota has not been estimated. This paper estimates the species number for sexual ascomycetes based on five different estimation approaches, viz. by numbers of described fungi, by fungus:substrate ratio, by ecological distribution, by meta-DNA barcoding or culture-independent studies and by previous estimates of species in Ascomycota. The assumptions were made with the currently most accepted, “2.2–3.8 million” species estimate and results of previous studies concluding that 90% of the described ascomycetes reproduce sexually. The Catalogue of Life, Species Fungorum and published research were used for data procurement. The average value of teleomorphic species in Ascomycota from all methods is 1.86 million, ranging from 1.37 to 2.56 million. However, only around 83,000 teleomorphic species have been described in Ascomycota and deposited in data repositories. The ratio between described teleomorphic ascomycetes to predicted teleomorphic ascomycetes is 1:22. Therefore, where are the undiscovered teleomorphic ascomycetes? The undescribed species are no doubt to be found in biodiversity hot spots, poorly-studied areas and species complexes. Other poorly studied niches include extremophiles, lichenicolous fungi, human pathogens, marine fungi, and fungicolous fungi. Undescribed species are present in unexamined collections in specimen repositories or incompletely described earlier species. Nomenclatural issues, such as the use of separate names for teleomorph and anamorphs, synonyms, conspecific names, illegitimate and invalid names also affect the number of described species. Interspecies introgression results in new species, while species numbers are reduced by extinctions.

Pyrrosia lingua (Thunb.); Farwell is an epiphytic fern belonging to Polypodiaceae. As a plant with high medicinal value, Py. lingua has been introduced and cultivated in worldwide. In this study, Py. lingua samples were collected in Guangzhou city, Guangdong Province, China, and endophytic fungal strains were obtained using tissue isolation. Isolated fungi were identified based on morphological characteristics and phylogenetic approaches. The phylogenetic analyses and pairwise homoplasy index was done using the sequence data of the internal transcribed spacer (ITS), beta-tubulin (tub2) and translation elongation factor 1-alpha gene (tef 1-α). Based on the combined approaches, a new species, Pestalotiopsis linguae and a new host record, P. nanjingensis have been identified. This is the first recorded Pestalotiopsis species on Py. lingua worldwide. The species descriptions and illustrations have been provided for the new species and the host record. The results of this study have an important contribution to understanding the endophytic fungal diversity of Py. lingua and provide an essential platform for better research on the application value of Py. lingua plants in the future.

Apiospora, an ascomycetous genus in Apiosporaceae, comprises saprobes, endophytes, and pathogens of humans and plants. They have a cosmopolitan distribution with a wide range of hosts reported from Asia. In the present study, we collected and isolated Apiospora species from Wurfbainia villosa and grasses in Guangdong and Yunnan provinces in China. Multi-locus phylogeny based on the internal transcribed spacer, the large subunit nuclear rDNA, the partial translation elongation factor 1-α, and β-tubulin was performed to clarify the phylogenetic affinities of the Apiospora species. Based on the distinctive morphological characteristics and molecular evidence, Ap. endophytica, Ap. guangdongensis, Ap. wurfbainiae, and Ap. yunnanensis are proposed. Descriptions, illustrations, and notes for the newly discovered species are provided and compared with closely related Apiospora species. An updated phylogeny of Apiospora is presented, along with a discussion on the phylogenetic affinities of ambiguous taxa.

The health and attractiveness of ornamental plants play key role in gardening and horticulture. They affect both the economical and ornamental value of the plants. In this study, we collected and isolated microfungi associated with dead petioles of dwarf date palm and living leaves of lady palm from Zhongkai University Garden, Guangzhou, China. Phylogenetic relationships were investigated based on multi-locus phylogeny of ITS, LSU, SSU and tef-1α sequence data. The morphology of the new collections was compared with all the relevant species. Based on the morphological comparison and multi-locus phylogeny, we introduce Byssosphaeria phoenicis sp. nov. and Pseudocoleophoma rhapidis sp. nov. in Melanommataceae and Dictyosporiaceae, respectively. Detailed descriptions and illustrations are provided with notes discussing allied species in Byssosphaeria and Pseudocoleophoma. Pathogenicity testing of P. rhapidis causing leaf spots on lady palm was proven and Koch’s postulates fulfilled. This is the first phytopathogenic Pseudocoleophoma species. The pathogenicity does not cause dieback, but the leaf spots reduce the aesthetical value of the plants.

The South China Botanical Garden (SCBG), one of the largest and oldest botanical gardens in China, conserves important plant germplasms of endangered species. Therefore, ensuring tree health and studying the associated mycobiome of the phyllosphere is essential to maintaining its visual aesthetics. During a survey of plant-associated microfungal species in SCBG, we collected several coelomycetous taxa. Phylogenetic relationships were evaluated based on the analyses of ITS, LSU, RPB2, and β-tubulin loci. The morphological features of the new collections were compared with those of existing species, emphasizing close phylogenetic affinities. Based on the morphological comparisons and multi-locus phylogeny, we introduce three new species. These are Ectophoma phoenicis sp. nov., Remotididymella fici-microcarpae sp. nov., and Stagonosporopsis pedicularis-striatae sp. nov. In addition, we describe a new host record for Allophoma tropica in the Didymellaceae. Detailed descriptions and illustrations are provided along with notes comparing allied species.