Part 1/1 of Engler's Syllabus of Plant Families - Blue-green Algae, Myxomycetes and Myxomycete-like organisms, Phytoparasitic protists, Heterotrophic Hetero -kontobionta and Fungi p.p. provides a thorough treatment of the world-wide morphological and molecular diversity of the Cyanoprokaryota, Acrasia and Eumycetozoa, Phytomyxea, the heterotrophic Heterokontobionta (Labyrinthulomycota, Oomycota), and the lower fungi (Chytridiomycota, Zygomycota and Glomeromycota). Recent DNA sequence data and advances in phylogenetic analysis brought tremendous changes to the interpretation of evolutionary relationships in every taxonomic rank, even in these lowermost plant groups, although their origin is still highly disputed. The authors followed the tradition of A. Engler with morphological-anatomical data, but are additionally incorporating the latest results from molecular phylogenies. This up-to-date overview of the Cyanoprokaryota, Acrasia, Eumycetozoa, Phytomyxea, Labyrinthulomycota, Oomycota, Chytridiomycota, Zygomycota and Glomeromycota will be a useful reference for a long time to come. Engler's Syllabus of Plant Families has since its first publication in 1887 aimed to provide both the researcher, and particularly the student with a concise survey of the plant kingdom as a whole, presenting all higher systematic units right down to families and genera of plants and fungi. In 1964, more than 45 years ago, the 12th edition of the well-known 'Syllabus der Pflanzenfamilien' ('Syllabus of Plant Families'), set a standard. Now, the completely restructured and revised 13th edition of Engler's Syllabus published in 5 parts and in English language for the first time also considers molecular data, which have only recently become available in order to provide an up-to-date evolutionary and systematic overview of the plant groups treated. In our 'molecular times' there is a vitally important and growing need to preserve the knowledge of the entire range of diversity and biology of organisms for coming generations, as there is a decline in 'classical' morphological and taxonomical expertise, especially for less popular (showy) groups of organisms. Accordingly, the 13th edition of Syllabus of Plant Families synthesizes both modern data and classical expertise, serving to educate future experts who will maintain our knowledge of the full range of Earth's biodiversity. Syllabus of Plant Families is a mandatory reference for students, experts and researchers from all fields of biological sciences, particularly botany.