Originally Posted by Baraka_Guru

Remember that buckwheat isn't a cereal grain; it's the seed of a flowering plant, rather than the seed of grasses. Beers that use buckwheat would do so to emphasize the variation on using a typical cereal grain by using something such as buckwheat.

Most beers stick to hops (a flower), barley (a grain), and wheat (a grain), and sometimes corn (maize) and rice (more grains).