The source of information taken in this book is the result of field work as well as laboratory experiments conducted in the Research Laboratory of University, Department of Botany, Ranchi University, Ranchi. Water bodies of the different districts of Jharkhand was visited in regular intervals for the collection of aquatic and semi aquatic plant species during the period from February 2015 to January 2019. The inventory of the aquatic and semi aquatic plant species will advance the knowledge of future researchers, Environmentalists and farmers and the students. It reflects the new record to the plant list of Jharkhand as well as the plant category of threatened and rare species. This is the first state flora on aquatic and semiaquatic plants apecies. To the best of our knowledge, this work is original. References earlier works have been duly acknowledged. Neither this, nor any substantially similar thesis has been or is being submitted for any other degree, diploma or any other qualification at any other University.