Book excerpt: The medicinal plants are highly dynamic life forms which have been used for thousands of years. With their wide variety of uses, medicinal plants have become important for human beings in various aspects such as therapeutic cures for all age groups, animals, and insects. These plants also play a vital role in food-chain management. They not only cure human ailments but also offer solutions for various problems in agricultural fields. The medicinal plants are being used for many other purposes as well. These include promoting general well being, regulating emotions and moods, healing physical injuries, etc. Medicinal plants are broadly categorized into four main categories herbs, fruits, vegetables, and fruits (flowers and leaves), roots, and so on. Most of the medicinal plants are being grown nowadays in tropical areas, mainly due to climatic changes. Due to this change, these plants have adapted to the changed conditions and can survive in very difficult conditions