Medicine and Natural Sciences: Chemistry in Botanical Classification contains the proceedings of the Twenty-Fifth Nobel Symposium held in Sodergarn, Sweden, on August 20-25, 1973. The papers explore the chemical approach to plant classification and cover topics ranging from chemosystematics and applications of special classes of compounds to insects and plant chemotaxonomy. Biosynthetic pathways in chemical phylogeny and some aspects of organic geochemistry are also discussed. This book is comprised of 32 chapters divided into five sections. The first chapter provides an overview of the chemical approach to botanical classification, with special reference to the higher taxa of Magnoliophyta. The reader is then introduced to chemosystematics and the construction of phylogenetic schemes, as well as the use of a chemical character for the classification of living organisms. The following chapters focus on The chemistry of disjunct taxa; homology of biosynthetic routes; and applications of special classes of compounds such as flavonoids. The systematic distribution of ellagitannins in relation to the phylogeny and classification of the angiosperms is also considered. The final chapter describes phytochemical and biological procedures for screening of plant materials. This monograph will be of value to botanists, plant taxonomists, and chemists.