Unveiling species diversity within Mortierellomycota from China X: Three new species in Linnemannia and one in Mortierella

The species of the Mortierellaceae family are diverse and widely distributed. Four new species in this family are proposed from rhizosphere soil through a comprehensive taxonomic approach that combined multi-locus (SSU-ITS-LSU-<i>RPB1</i>-<i>Act</i>) phylogenetic analyses with detailed morphological examination. This study describes and illustrates these taxa, clarifying their morphological features from closely related species and their phylogenetic positions within the family. <i>Linnemannia chlamydospora</i> <b>sp. nov.</b> (phylogenetically proximate to <i>L. longigemmata</i>) is characterized by the abundant production of thick-walled chlamydospores. <i>Linnemannia ovalispora</i> <b>sp. nov.</b> (a sister taxon to <i>L. rugosa</i>) is distinguished by its oval sporangiospores. <i>Linnemannia yunnanensis</i> <b>sp. nov.</b> (closely allied to <i>L. bainierella</i>) is characterized by its oval chlamydospores and is named after Yunnan Province, its type locality. <i>Mortierella irregularispora</i> <b>sp. nov.</b> (clustering with <i>M. parvispora</i>) is distinguished by its irregularly shaped sporangiospores. As this is the tenth instalment of our systematic survey of Mortierellomycota diversity in China, this study expands the global species inventory of Mortierellaceae to 158.