This book is ideally meant to be a standard textbook of Botany and allied subjects like Zoology, Environmental Sciences, Microbiology, Ecology, Forestry, Geography, Biotechnology etc. for UG and PG students. The book is divided into three sections: Ecology and Environmental Biology, Economic Botany and Pharmacognosy. The first section has four chapters: Ecology, Biodiversity & Conservation; Phytogeography & Endemism; and Environmental Biology which are interdisciplinary in nature. The second section (Economic Botany) includes nature's biological resources with regard to their sources, uses and application. The third section i.e. Pharmacognosy is an applied branch encompassing various sources and applications of crude drugs. The book is appropriately illustrated and documented, possesses inclusive accounts for students, teachers and researchers.