Buckwheat is not a grain and has a low glycemic index.
Buckwheat refers to plants in two genera of the dicot family Polygonaceae: the Eurasian genus Fagopyrum, and the North American genus Eriogonum. The crop plant, common buckwheat, is Fagopyrum esculentum. Tartary buckwheat (F. tataricum Gaertn.) or "bitter buckwheat" is also used as a crop, but it is...