This book is about crop plant varieties developed by local farmers - commonly referred to as farmers' varieties - and policies to increase the share of benefits farmers receive from the use of those varieties. This subject is problematic because there are no fixed taxonomic or legal definitions of farmers' varieties. The book aims to clarify the issues by examining: " biological and social complexities involved in answering the questions, 'What is a farmers' variety?' and 'How can you tell them apart?' " the evolution of the concept of 'Farmers rights,' starting from the dawn of 'genetic resources' as a subject worthy of international attention, to the first legal recognition of the concept of Farmers Rights in an international treaty in 2001, through to current efforts to develop national level policies and laws" outstanding policy-making challenges linked to the absence of fixed taxonomic or legal definitions of farmers' varieties. Various solutions are considered, based on revised or new definitions of farmers' varieties that reflect the biological and cultural realities in which they are produced, and the relative costs and benefits of attempting to implement each of the policies considered " the manner in which public debate concerning the policy options considered in the book has evolved over the course of the last 20 years, and how that evolution compares with actual experiences implementing those policies. " case studies of actual situations 'in the field' where farmers, researchers and policy advocates have been confronted with the issues raised in this book.