Novel Helicotubeufia and Tubeufia (Tubeufiaceae, Tubeufiales) species from terrestrial habitats in Hainan Province, China

Helicosporous hyphomycetes are a group of fungi, characterised by coiled or spiral conidia and are known for their potential to produce bioactive secondary metabolites. During a survey of helicosporous hyphomycetes, four isolates were obtained from decaying wood in Hainan Province, southern China. Based on phylogenetic analyses of a combined dataset (ITS, LSU, <i>tef</i>1-α and <i>rpb</i>2) and morphological characteristics, two novel species, <i>Helicotubeufia qixianlingensis</i> and <i>Tubeufia diaoluoshanensis</i>, are introduced. Comprehensive descriptions, illustrations and phylogenetic analyses supporting the taxonomic placement of these new taxa are provided. Notably, <i>H. qixianlingensis</i> represents the first record of <i>Helicotubeufia</i> from a terrestrial habitat, thereby expanding the known diversity of tropical terrestrial fungi.