New species and records of Helicosporium sensu lato from Taiwan, with a reflection on current generic circumscription

Abstract

This paper describes and illustrates five species of Helicosporium sensu lato, which represents the partial result of an investigation of fungal diversity associated with submerged wood and decaying culms of Miscanthus floridulus (Poaceae) from freshwater streams in Alishan area, Chiayi County, Taiwan, which was carried out during the years 2016 and 2017. Neohelicomyces longisetosus sp. nov. and Helicosporium flavidum sp. nov. are described and illustrated; the former is proposed based on molecular and morphological data, whereas the latter is based on morphology only. Pseudohelicomyces talbotii, a new record for Taiwan, is renamed as Parahelicomyces talbotii because the former genus was a homonym and thus illegitimate. The other six illegitimate Pseudohelicomyces species are transferred to Parahelicomyces as new combinations. Two other species, namely Acanthohelicospora guianensis and Neohelicosporium sympodiophorum, are also new records for Taiwan. A taxonomic key to Helicosporium sensu stricto is provided. Current generic circumscription of helicosporous taxa based on phylogeny is briefly discussed.