My purpose is to introduce a special issue of Seed Science Research devoted to papers resulting from material presented at Seed Ecology V held in Caeté, Brazil on 21–25 August 2016. An overview of the field of seed ecology is presented that includes a short summary of what I consider to be the eight basic subcategories of this field, and the five new areas of investigation that have developed as extensions and/or recombinations of basic areas. Seed ecology conferences allow researchers to communicate with each other and build new collaborative relationships. At Seed Ecology V, information was presented that related to each area of seed ecology. The nine papers in this special issue are a small sample of the information presented at the meeting, and each paper is briefly described and placed into one of the subcategories of seed ecology research.