The Buckwheat (Fagopyrum esculentum) belongs to Polygonaceae (the Knotweed family). It is an annual herb that is native to Central Asia through eastern East Asia. It was introduced into Japan in 8th century via the Korean Peninsula. This herb can reach 30-90 cm in height and the leaves are triangular and alternate. The racemes are borne on the stem apices and axils, and bloom white flowers in fall. The seeds are blackish-brown and acute triquetrous. They are used for food after milling flour. This herb prefers cool arid areas. It has been cultivated in the northern region of Japan from long ago. In Chinese, it is called "蕎麦" (qiao mai).