<i>Aquimassariosphaeria yunnanensis</i> sp. nov. (Lindgomycetaceae, Pleosporales) from a Lentic Habitat in Yunnan Province, China

A survey of lignicolous freshwater fungi in Yunnan Province, China, resulted in the discovery of a new species, Aquimassariosphaeria yunnanensis. Morphological characteristics are described, and DNA sequences from ribosomal and protein‐coding loci are analyzed to determine its phylogenetic relationships with other related species in the genus Aquimassariosphaeria . Aquimassariosphaeria yunnanensis sp. nov. is typical of the genus and characterized by micro‐ to macronematous, unbranched conidiophores that extend laterally, forming integrated, monoblastic, cylindrical, pale to dark brown conidiogenous cells, and long, solitary, scolecosporous, unbranched, multiseptate, smooth‐walled, grayish brown to dark brown conidia that proliferate apically. Multigene phylogenetic analyses of a combined ITS, LSU, SSU, tef1 ‐ α, and rpb 2 DNA sequence dataset generated from Maximum Likelihood and Bayesian Inference analyses indicated that A. yunnanensis forms a separate branch and is closely related to other species in Aquimassariosphaeria (Lindgomycetaceae, Pleosporales). Results from the pairwise homoplasy index (PHI) tests revealed no significant genetic recombination (Φ w = 1.0) between A. yunnanensis and closely related species, A. aquatica and A. typhicola . This study provides a detailed morphological description and illustration of A. yunnanensis and an updated phylogeny of the family Lindgomycetaceae in Pleosporales.