Lignicolous freshwater fungi of the pan Qinghai-Xizang Plateau, China

The Qinghai-Xizang Plateau (Q-X Plateau) is a critical ecological region, and often referred to as the “Asia Water Tower” due to its role in sustaining major river systems. Its unique environment fosters a rich fungal diversity, including freshwater ascomycetes, which thrive on submerged plant substrates in freshwater habitats and play key roles in nutrient cycling and ecosystem functioning. To systematically report fungal species in this region, we have initiated a series on the fungi of Q-X Plateau. This is the second contribution in this series, focusing on lignicolous freshwater ascomycetes, in which 84 taxa distributed in three classes, 26 orders, 37 families and 53 genera are described and illustrated. Taxa include three new families, five new genera, 42 new species, and 12 new geographical distribution reports. Three new families are Acronigrasporaceae (Natipusillales), Longirostraceae (Pleosporales) and Xizangmycetaceae (Pisorisporiales); new genera are Acronigraspora (Acronigrasporaceae, Natipusillales), Catenatimuriformis (Phaeoseptaceae, Pleosporales), Hyaloambispora (Microthyriaceae, Microthyriales) Longirostrum (Longirostraceae, Pleosporales), and Xizangmyces (Xizangmycetaceae, Pisorisporiales); new species comprise Acrodictys altitudinalisa, Acrogenospora alticampestriicola, Acronigraspora subsphaerica, Acronigraspora zhuomulariensis, Aurantiascoma xinjiangensis, Brachiosphaera radiaticonidiosa, Brachysporium nielamuense, Catenatimuriformis sporodochialis, Chaetopsina motuoensis, Chaetosphaeria aseptata, Chloridiopsiella septate, Cladophialophora kaiduensis, Conioscypha breviconiophora, Conioscypha motuoensis, Conioscypha subglobosa, Cordana reniformis, Dematiosporium dictyosporum, Dematiosporium phaeohyphum, Gamsomyces namco, Gohteikhimyces dulongjiangensis, Hongkongmyces fusiformis, Hyaloambispora drungiorum, Hyaloambispora reniformis, Junewangia chenyue, Kirschsteiniothelia mucosa, Lentistoma motuoense, Longirostrum aquaticum, Neohelicosporium xinjiangense, Pleurotheciella bambusisiliquosa, Pseudoascotaiwania aquatica, Pseudostanjehughesia nielamuensis, Savoryella daemonocula, Spadicoides hydei, Sporidesmiella yadongensis, Sporidesmium bostenicum, Sporidesmium mucilaginosum, Sporidesmium napaense, Sporoschisma hyalomucilaginosum, Thysanorea hyaloconidia, Wiesneriomyces aquaticus, Xizangmyces aquaticus and Xylolentia subhyalina; new geographical records are Bactrodesmiastrum pyriforme, Bactrodesmium diversum, Bactrodesmium obovatum, Cordana crassa, Halosphaeriopsis mediosetigera, Jennwenomyces navicularis, Pleurothecium recurvatum, Ramophialophora vesiculosa, Scedosporium minutisporum, Sterigmatobotrys macrocarpus, Vanakripa mucosa, Vargamyces aquaticus. The morphological and phylogenetic evidences are used to support the establishment of these new taxa and the accuracy of their taxonomic placements.