[The taxonomy of the genera of Alternaria (Nees: Fr)]

The identification of species in Alternaria (Nees:Fr.) is mainly based on shape, size and septation of conidia. Because of the great variances in these marks a reliable determination of species in that genus sometimes is difficult. 137 strains of Alternaria isolated from forage are attempted to identify. Various macro- and micromorphological methods used are described as well as their sources of errors. It is emphasized that a stringent standardization of all determination methods is necessary. Beyond it there are discussed some molecular biological and biochemical characteristics to complete the data of taxonomy in the genus of Alternaria.