Rye
Sing a song of sixpence, a pocket full of rye…. ~ English nursery rhyme
Rye is closely related to barley and wheat. Though long known, rye was long dismissed as inferior to wheat.
Rye gained ground in central and eastern Europe during the Middle Ages. Rye grows well in much poorer soils than other cereal grains and withstands cold weather better.
Because it is difficult to separate the germ and bran from the endosperm of rye, rye flour is often more nutritious than wheat, which is typically refined.
Rye is roughly as nutritious as other caryopses. Rye is notably high in manganese, phosphorus, copper, and magnesium.