a genus of plants of the buckwheat family, including the buckwheat Fagopyrum esculentum; in some classifications included in the genus Polygonum.

The genus Fagopyrum in the flowering plant family Polygonaceae includes two important crop plants, the Buckwheat or Japanese Buckwheat Fagopyrum esculentum, and the Tartary Buckwheat Fagopyrum tataricum. They have similar uses, and are classed as pseudocereals, i.e. they are used in the same way as cereals but do not belong the grass family Gramineae.