Apomixis, clonal reproduction through seed, is divided into sporophytic (nucellar embryony) and gametophytic apomixis. This book focuses on the latter type. Gametophytic apomixis, while rare, is taxonomically widespread, notably among grasses and Asteraceae. Detection methods have advanced significantly, employing flow cytometry and advanced microscopy techniques. The genetic, molecular, and developmental mechanisms behind apomixis involve modifications preventing meiosis and enabling parthenogenesis. Understanding these mechanisms and applying approaches such as forward genetics and mutagenesis holds an important potential for agricultural innovation. Numerous genetic, ecological, and evolutionary questions remain open, highlighting apomixis as an important field for ongoing scientific research.