Notes on the genus Hysterographium (Ascomycota, Hysteriaceae) in southern South America

During a taxonomical survey of the family Hysteriaceae from the Patagonia region (Argentina and Chile), the species of Hysterographium were revised, based on personal collections and Spegazzini's and Rehm's type material. Two cosmopolitan species, H. flexuosum and H. subrugosum. were recorded. Microscopic features are described, illustrated, and their taxonomic position and geographical distribution are commented. H. magellanicum, H. fuegianum and H. fuegianum f. intermedium are synonymized with H. flexuosum, and H. cylindrosporum with H. subrugosum.