The purpose of this book is to provide pharmacognostical information of drugs, their classification, adulteration. Quality control and pest control. The presence of the natural products found in trace amounts are also mentioned. The pharmacological activities of the important drug constituents are included. It is hoped that new entries would add immensely to the usefulness of the book by highlighting the results of chemical and biological studies of the herbal drugs. The source book is organized into 25 chapters. Each chapter covers general information. The drugs include information concerning biological sources, geographical distribution, morphology, histological characters, chemical constituents, chemical tests, medicinal uses, adulteration or substituents and pharmacological activities. The chapters offer a view over the -enormous diversity of natural chemical molecules. The stereostructures of phytoconstituents are illustrated to introduce most of the concepts required for the study of natural products.