The term ‘seaweed’ represents an assemblage of a diverse group of photosynthetic aquatic plants that are exceptionally unique in their form, function, structure, and biochemical composition. In Far East Asian countries, seaweeds are popularly utilised in human food preparations, in addition to being used as a source of raw material for the extraction of industrially important phycocolloids and agro-based products. More recently, there has been growing interest in the application of seaweed ingredients in beauty and novelty food products, nutraceuticals, bioplastics, and beverages, among others, as well as its potential as a source for biofuels Seaweed, though it is a primitive plant, has complex morphological structure, meaning species-level identification of an individual seaweed is a difficult task. This volume describes the identification characteristics of 256 seaweed species collected from the south-east coast of India; comprising 71 species of green algae (chlorophyceae), 46 species of brown algae (phaeophyceae) and 139 species of red algae (rhodophyceae). Key taxonomic characteristics detailed here allow the confirmation of identification of different kinds of seaweed. As such, the book forms an excellent field guide for beginners in seaweed research, marine botanists, students, researchers, divers, and anyone who has interest in knowing more about seaweeds.