Texas microfungi: on the taxonomic placement of Flosculomyces floridaensis in Zygosporiaceae

The phylogenetic relationships and taxonomic placement of the anamorph Flosculomyces floridaensis are explored for the first time based on a strain isolated from a culturable air sample collected indoors in Texas, USA. Unpublished sequences obtained online from six well-characterized strains isolated in Japan were also included. Phylogenetic analyses using DNA sequence data from two different nuclear ribosomal loci (ITS, LSU) suggest that the fungus is a member of Xylariales (Sordariomycetes) and forms a distinct monophyletic lineage within Zygosporiaceae. The genus is recognized as a phylogenetically well-circumscribed taxon in agreement with its peculiar and unique morphology. The monophyletic Zygosporiaceae is recovered as five distinct and well delimited lineages based on the disparate morphologies of their anamorphs whereas Zygosporium was resolved as paraphyletic within the family. Flosculomyces floridaensis has not previously been reported in the continental USA outside its type locality in Florida and is recorded here for the first time from Texas.