The main sections of the book are devoted to describing the history of the formation of genosystematics of higher plants (BP), the properties of their nuclear, chloroplast and mitochondrial DNA and methods of genosystematics. An overview of recent developments in BP genosystems, from bryophytes to angiosperms, is provided. A number of examples show how genosystematic methods have produced results that shed light on the evolution of BP, clarifying the phylogenetic relationships of their taxa.