Indian has one of the oldest, richest and most diverse cultural traditions associated with the use of medicinal plants. We also have a vast and inexhaustible resource of drugs of plant origin as nature has provided us with a rich storehouse of herbal remedies to cure all mankind's ailments. Some of them are widely cultivated and others are found in plenty. Medicinal plants have their values in various chemical compounds available in various parts such as leaves, stems, roots, seeds, bark, wood etc. These have been determined, by their pharmacological action of active principles, which produce specific physiological action in human body. The more important of these substances are alkaloids, glycosides, essential and fatty oils, resins, gums, mucilage, tannins etc. In addition, the natural wealth of flora is increasingly threatened by the pressures of population explosion, commercial exploitation, expanding cultivation of agricultural crops, developmental projects of urbanization etc.