Genus and species are different: Cucumis sativus is a plant of Chenopodium of Apocynaceae, and Ascopodium is a perennial herbaceous vine of Ascopodium of Apocynaceae.

The distribution range is different: sweet potato is distributed in northeast China, North China, Inner Mongolia, Shaanxi, Gansu, Xinjiang and Jiangsu provinces, while Japanese radish is distributed in Japan, North Korea, Russian Federation and China.