Two new Stictidaceae species from grasslands in Yunnan province, China

Stictidaceae is characterised by a wide geographic distribution and diverse ecological roles. It has recently been the focus of taxonomic research in China. In this study, we describe two new asexual Stictidaceae species that we presume to be saprobes: Glomerobolus poacearum and Ostropomyces yunnanensis. The specimens were collected from decaying stems of unidentified herbaceous and Poaceae hosts in the Yunnan Dashanbao Black-necked Crane National Nature Reserve, China. Our approach combines morphological and multi-locus phylogenetic analysis, utilising LSU, ITS, mtSSU and rpb2 markers. Glomerobolus poacearum sp. nov., was collected on decayed aquatic grass stems. In our phylogeny, it forms a well-supported clade with G. gelineus, the type of the genus. The species differs from G. gelineus in having comparatively smaller hyphoma, lobes and ballistic propagules that are spherical or fan-shaped when swollen. The discovery of Glomerobolus poacearum on Poaceae species within China are new observations of plant associates and geographical distribution in the genus. Ostropomyces yunnanensis sp. nov., was collected on a stem of a herbaceous plant. In our phylogenetic analysis, it forms a well-supported clade with G. gelineus, the type species of the genus and is characterised by the production of conidiomata with forcible discharge. Ostropomyces yunnanensis is distinguishable from the asexual morph of O. pruinosellus by possessing larger pycnidial conidiomata, which feature multiple locules of conical or irregular shapes and by having larger conidia that are 0-4-septate. These taxonomic contributions enrich our understanding of the diversity, evolutionary relationships and ecological interactions within Stictidaceae.