There is no existence of life without plants. Plants are the essential foundation of medicine. Some important drugs that are still in use today are derived from traditional medicinal herbs. The hunt for new medicines has engaged ethnobotany and ethnopharmacology—a new route as an important source of knowledge, which led toward different sources and classes of compounds. Nowadays, studies on structure-activity relationships, and their impact on the design of novel drugs have rendered them one of the utmost valuable and thus significant accomplishments of pharmacochemistry, an advance constituent in the group of pharmaceutical sciences. In this paper, we have discussed the historical importance of medicinal plants, geographical importance throughout the world, some important historical observations of medicinal plants, and leading drugs of plant origin which are still being used to treat various ailments, with or without any structural modifications.
