Buckwheat and Herbaceous plant

Buckwheat noun - A member of the 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.

Herbaceous plant and buckwheat are semantically related. In some cases you can use "Herbaceous plant" instead a noun "Buckwheat".

Herbaceous plant noun - A plant lacking a permanent woody stem; many are flowering garden plants or potherbs; some having medicinal properties; some are pests.

Buckwheat and herbaceous plant are semantically related. Sometimes you can replace term "Buckwheat" with "Herbaceous plant", this terms are similar.