Medicinal plants are nature's hidden and to a large extent unexplored treasure. Although they have been used as a source of safe and effective medicine since time immemorial, this potential resource has hardly been commercially tapped. Over millennia that followed the effective agents amongst them were selected by the process of trial, error, empirical reasoning and even by experimentation. The ancient civilization of India, China, Greece, Arab and other countries of the world developed their systems of medicine independent of each other but all of them were predominantly plant based. This book may be able to provide a lucid discourse on the subject to the person seeking a brief information on the topics.