The book is based on the author's life time experience in exploring and researching the genus Avena. It describes some great events in oat research and minor stories along the way. It will be of interest and value to all those working with oats and to students and scientists of crop evolution, including those dealing with collecting and conserving wild genetic resources. A first part deals with the morphology and taxonomy of the genus and a classification based on the biological species concept is presented. A further part is devoted to the author’s research accomplishments in this genus. It describes morphological characters distinguishing between diploids and tetraploids of series Eubarbatae, the genetic relationships between them, and the mode of origin of the tetraploid form. The section Denticulatae, to which the common oat belongs, is extensively treated. Further, oat domestication and the newly domesticated protein rich A. magna are described. A third part dealswith wild genetic resources of oat.