- buckwheat, Polygonum fagopyrum, Fagopyrum esculentum - or member of genus Fagopyrum; annual Asian plant with clusters of small pinkish white flowers and small edible triangular seeds which are used whole or ground into flour
--1 is a kind of herb, herbaceous plant
--1 is a member of Polygonum, genus Polygonum
--1 has parts: buckwheat