Fungi are an essential component of any ecosystem and have diverse ecological roles, ranging from endophytes to epiphytes and pathogens to saprobes. The current estimate of fungal endophytes is around 1 million species, however, we estimate that there is likely over 3 million species and only about 150,000 fungal species have been named and classified to date. Endophytes inhabit internal plant tissues without causing apparent harm to the hosts. Endophytes occur in almost every plant from the coldest climates to the tropics. They are thought to provide several benefits to host plants and improve the hosts’ ability to tolerate several abiotic and biotic stresses. Endophytes produce secondary metabolites with biotechnological, industrial and pharmaceutical application. Some endophytes appear to be host-specific, while some are associated with a wide range of hosts. We discuss the importance of endophytes. The ability to switch lifestyles from endophytes to pathogens or saprobes is discussed. Interactions between endophytes and hosts based on fossil data is also highlighted. Factors that influence the specificity in endophytes are discussed. We argue that the endophytic lifestyle is a common strategy in most fungi and that all fungi have endophytic ancestors. We critically evaluate the influence of co-evolution based on fossil data. We hypothesise the influence of specificity on the estimated number of endophytes and overall species numbers, and present examples of metabolites that they produce. We argue that studying endophytes for novel compounds has limitations as the genera recovered are limited. However, if saprobes were chosen instead, this would result in a much higher species diversity and undoubtedly chemical diversity.

Guizhou and Yunnan Provinces (Yungui Plateau) in Southwestern China are well known as biodiversity hotspots. We introduce two new species in this study viz., Mucispora hydei (in Fuscosporellaceae, Fuscosporellales, Sordariomycetes) and Tolypocladium cucullae (Ophiocordycipitaceae, Hypocreales, Sordariomycetes) and six new records based on morpho-molecular analyses. Full descriptions, color photographs and phylogenetic trees to indicate the placements of new species are provided.

In this study, fungal specimens of the family Diatrypaceae were collected from karst areas in Guizhou, Hainan and Yunnan Provinces, China. Morpho-molecular analyses confirmed that these new collections comprise a new genusPseudodiatrype, three new species (Diatrype lancangensis,Diatrypella pseudooregonensisandEutypa cerasi), a new combination (Diatrypella oregonensis), two new records (Allodiatrype thailandicaandDiatrypella vulgaris) from China and two other known species (Neoeutypella baoshanensisandParaeutypella citricola). The new taxa are introduced, based on multi-gene phylogenetic analyses (ITS, β-tubulin), as well as morphological analyses. The new genusPseudodiatrypeis characterised by its wart-like stromata with 5–20 ascomata immersed in one stroma and the endostroma composed of thin black outer and inner layers of large white cells with thin, powdery, yellowish cells. These characteristics separate this genus from two similar generaAllodiatrypeandDiatrype. Based on morphological as well as phylogenetic analyses,Diatrype lancangensisis introduced as a new species ofDiatrype. The stromata ofDiatrype lancangensisare similar to those ofD. subundulataandD. undulate, but the ascospores are larger. Based on phylogenetic analyses,Diatrype oregonensisis transferred to the genusDiatrypellaasDiatrypella oregonensiswhileDiatrypella pseudooregonensisis introduced as a new species ofDiatrypellawith 8 spores in an ascus. In addition, multi-gene phylogenetic analyses show thatEutypa cerasiis closely related toE. lata, but the ascomata and asci ofEutypa cerasiare smaller. The polyphyletic nature of some genera of Diatrypaceae has led to confusion in the classification of the family, thus we discuss whether the number of ascospores per asci can still be used as a basis for classification.

In a comprehensive survey of fungi conducted in the northern (Chiang Rai Province) and southern (Narathiwat Province) regions of Thailand, several xylariales-like specimens were discovered. Through the integration of molecular phylogeny and morphological analyses, one previously undocumented taxon,Oxydothis narathiwatensissp. nov., was identified, along withXylaria bawanglingensisandHypoxylon hypomiltumas new host and geographical records fromAfzelia xylocarpa, andDalbergia cana, respectively. In addition,Annulohypoxylon thailandicumwas identified as a new host record fromSwietenia macrophyllain Thailand. The morphological characters, including ascomata, asci, and ascospores, were compared with knownOxydothis,Xylaria,Hypoxylon, andAnnulohypoxylonspecies. Multi-locus phylogenetic analyses based on ITS, LSU, and SSU (for Oxydothidaceae), ITS,rpb2,tub2, andact(for Xylariaceae), and ITS, LSU,rpb2, andtub2(for Hypoxylaceae) gene regions were carried out to refine the taxonomic classifications of these specimens further. This research contributes to understanding fungal diversity in these ecologically significant regions, highlighting insights into the relationships among xylariales-like species.

Xylariales members have conspicuous to inconspicuous perithecia with unitunicate asci. The most known species are endophytes and saprobes, known to produce secondary metabolites with fundamental importance in the pharmaceutical and chemical industries. The current study collected samples from decaying barks of Quercus kingiana at Doi Inthanon National Park, Thailand. Based on morphological features coupled with combined gene analyses of ITS, LSU, rpb2 and tub2 sequence data, the isolates were identified as Xylaria karsticola and Jackrogersella minutella, belonging to Xylariaceae and Hypoxylaceae, respectively. This study provides the first geographical records of X. karsticola and J. minutella in Thailand and the first records of these species on Quercus kingiana.