Freshwater Ascomycetes: Hyalorostratum brunneisporum, a new genus and species in the Diaporthales (Sordariomycetidae, Sordariomycetes) from North America

Hyalorostratum brunneisporum gen. et sp. nov. (ascomycetes) is described from freshwater habitats in Alaska and New Hampshire. The new genus is considered distinct based on morphological studies and phylogenetic analyses of combined nuclear ribosomal (18S and 28S) sequence data. Hyalorostratum brunneisporum is characterized by immersed to erumpent, pale to dark brown perithecia with a hyaline, long, emergent, periphysate neck covered with a tomentum of hyaline, irregularly shaped hyphae; numerous long, septate paraphyses; unitunicate, cylindrical asci with a large apical ring covered at the apex with gelatinous material; and brown, one-septate ascospores with or without a mucilaginous sheath. The new genus is placed basal within the order Diaporthales based on combined 18S and 28S sequence data. It is compared to other morphologically similar aquatic taxa and to taxa reported from freshwater habitats that share affinities to the Diaporthales..