The pleosporalean anamorph Hermatomyces amphisporus is recorded for the first time from the U.S.A. based on several specimens collected on Sabal minor (Arecaceae) duringmycological surveys carried out in the state of Texas. Phylogenetic analyses of novel DNA sequence data belonging to four nuclear regions (ITS rDNA, EF1-, RBP2, -TUB) revealed its taxonomic position within the monotypic family Hermatomycetaceae (Pleosporales, Dothideomycetes) in congruence with its morphological features.
A description of the fungus in culture is provided here for the first time. Interestingly, apart from the lenticular conidia, also cylindrical conidia were formed together with chlamydosporous structures and pycnidia producing hyaline, nonseptate conidia.
Further notes on the morphology on natural substrate, ecology and distribution in the U.S.A. and worldwide of this rare fungus are provided. The recently introduced species H. bauhiniae, which presents morphological characteristics different from the typical Hermatomyces spp., is found to be based on a confusing description, thus a different genus should be found to accommodate it.