In this talk, I explore “origin hypotheses” of bread wheat proposed in the 20th century. Bread wheat as a major staple had attracted various speculations about its history based on scientific and cultural arguments. In the first half of the 20th century, the crop was often associated with civilization and “civilized races,” and was also assumed to have a relatively short history. In the 1920s, the Japanese plant geneticist Hitoshi Kihara criticized this idea of the recent origin because it implied, as he understood, that the crop entered the East only after the Western imperial nations approached the East. About 20 years later, an American team of botanists proposed immediately after the Second World War a similar hypothesis that bread wheat had arisen recently in the “European side” of the Caucasus, the great boundary between Asia and Europe, and claimed that East Asia in ancient time did not have bread wheat. Opposing their idea, Kihara proposed an alternative hypothesis that placed the origin within the great boundary in much older time and speculated that the birthplace served as the common resource for both Eastern and Western sides. Based on these hypotheses of the origin of wheat, I would like to discuss how cultural meanings attached to crops could affect discussions of the origin/history of the plants.