A vast array of natural organic compounds, the products of primary and secondary metabolism, occur in plants. The purpose of this dictionary is to provide basic information, including structural formulae, on plant constituents, with emphasis on those that are biologically active. This text profiles over 3000 substances from phenolics and alkaloids through carbohydrates and plant glycosides to oils and triterpenoids. For each substance, the author presents the trivial name, synonyms, structural type, chemical structure showing stereochemistry, molecular weight and formula, natural occurrence, biological activity and commercial or other use. Key references are provided for each class and subclass. It also reviews antifungal agents, with CAS numbers wherever possible, for all compounds to provide ready access to the original literature.