Lays out the phylogenetic system of all plants (including fossils) from plant-like procaryotes, lower plant-like protistan organisms, algae, and fungi to mosses and higher vascular plants. Each family of plants is briefly characterised with diagnosis and a full synonymy from 1753 (the year of Linnaeus' Species Plantarum), in some cases with detailed infrafamilial classification. This volume supersedes the Syllabus der Pflanzanfamilien, initiated by the German botanist Adolf Engler in 1892.