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, tef1-α and rpb2) and morphological characteristics, two novel species, Helicotubeufia qixianlingensis and Tubeufia diaoluoshanensis, are introduced. Comprehensive descriptions, illustrations and phylogenetic analyses supporting the taxonomic placement of these new taxa are provided. Notably, H. qixianlingensis represents the first record of Helicotubeufia from a terrestrial habitat, thereby expanding the known diversity of tropical terrestrial fungi.