Discussions around the policy questions associated with farmers’ varieties and their possible protection have generally tended to treat farmers’ varieties as a monolithic entity. This notion is somewhat surprising as it denies the very diversity that is at the heart of farmers’ varieties. This chapter will examine through biological and cultural lenses the various attempts to define farmers’ varieties in an effort to isolate, if not clarify, some of the technical difficulties that beset a seemingly simple question such as, ‘Can we identify a landrace?’