Plant classification is the practice of placing known plants into categories or groups in order to establish a relationship. It follows a system of rules that standardizes the results and the group's successive categories into a hierarchy. The classification of plants provides an organized system for the cataloging and naming of the future specimen. It ideally reflects scientific ideas about inter-relationships between plants. Biodiversity refers to the variety and variability of life on earth. It acts as a measure of variation at the ecosystem, genetics and species level. The distribution of biodiversity of plants varies greatly across the globe, as well as within the region. Taxonomic diversity of plants is measured at the level of species diversity. This book includes some of the vital pieces of work being conducted across the world, on various topics related to plant classification and biodiversity. Its aim is to present researches that have transformed this field of study and aided its advancement. It is an essential guide for both academicians and those who wish to pursue this discipline further.