The word "cultivar" originated from the need to distinguish between wild plants and those with characteristics that arose in cultivation, presently denominated "cultigens". This distinction dates to the Greek philosopher Theophrastus (370–285 BC), the "Father of Botany", who was keenly aware of this difference. Botanical historian Alan Morton noted that Theophrastus in his "Historia Plantarum" ("Enquiry into Plants") "had an inkling of the limits of culturally induced (phenotypic) changes and of the importance of genetic constitution" ("Historia Plantarum", Book 3, 2, 2 and "Causa Plantarum", Book 1, 9, 3).