Frullania as a hotspot for hypocrealean ascomycetes: ten new species from Southeastern North America

The genus Frullania (Frullaniaceae, Porellales, Jungermanniopsida) comprises 21 species in Southeastern North America. Screening about 850 independent collections of common species of Frullania taken from the hark of trees in Alabama, Georgia, Mississippi, North Carolina, Tennessee, and Virginia revealed a surprisingly high number of parasitic fruit-body forming ascomycetes. Particularly well represented are the Hypocreales (Sordariomycetes), of which 14 species (out of 17 occurring on Frullania worldwide) in five genera on eight host species are documented here based on 235 specimens. The genera Bryotria, Laniatria, and Periantria are proposed as new as well as the following ten species: Bryocentria biannulata, B. chlysothrix, B. lusor, B. navicula. B. pentarnera. Bryonectria anisopoda, Bryotria adelpha, B. urophora, Laniatria myxostoma, and Periantria bellacaptiva. Three new combinations are proposed. Calonectria frullaniae is transferred to Periantria. Nectria foertheri (on Porella sp.) and N. lagodes to Bryotria. Bryocentria brongniartii, Bryonectria callicarpa. Bryotria lagodes, and Periantria frullaniae are new records for North America. The latter species which destroys developing sporophytes within the perianths was found to be by far the most frequent. The hypocrealean fungi on Frullania in Southeastern North America are much more diverse than those of Central Europe. Biotrophic and necrotrophic species occur in both regions. The main distinguishing characters are size and colour of perithecium, structure of the perithecial wall, and size, shape and septation of the ascospores. Perithecia sometimes occur in high densities (up to eight per square mm) and, in spite of their small size, are relatively conspicuous due to their vivid colouration. Nevertheless, beyond the present study, knowledge of the Frullania inhabiting ascomycetes in North America is almost non-existent.