Ferns, collectively, represent an ancient species of vascular plant which has a direct connection to the beginning of life on Earth. Today they are valued for their ornamental appeal, environmental benefit or as sources of health benefiting metabolites. Current pteridology, the study of fern, encompasses a wide range of research activities including, but not limited to, plant physiology, stress tolerance, genetics and genomics. The goal of this book is to compile the most relevant research done with ferns during the last decade. It is organized into four parts: I, Biology and Biotechnology; II, Evolution and Conservation; III, Metabolism and Genetic Resources, and IV, Environment. Each section reveals the utilization of ferns as a tool to explore challenges unique to plant development and adaptation. This project represents our collective effort to raise the awareness of ferns as a model system to study higher plant functions. Among the distinctive features of our proposed book are: (i) a wide range of topics with contributing researchers from all around the world, and (ii) recent advances of theoretic and applied knowledge with implications to crop species of economic value.