The genus Phytopythium is a relatively new group of organisms distinguished from the Pythium genus. These are organisms closely related to Pythium and Phytophthora, with similar structure and biology. Despite many similarities, this genus is characterised by several morphological features that allow it to be easily identified. Until now, more than 20 species belong to this genus, most of which are saprophytic organisms. However, there is also a group of species particularly dangerous to plants. These species include, among others, Pp. litorale, Pp. helicoides and Pp. vexans. The purpose of this work was to collect information about these organisms and present them in a condensed form. The study contains basic information about the history of the type of separation, differences in morphology distinctive genus of Phytopythium, Phytophthora and Pythium and information about diseases and host plants. Information is also provided on the potential threat posed by these organisms to forest ecosystems.
