Emmer or hulled wheat (Triticum dicoccum). This was one of humanity's first domesticated crops, related to eikorn (Triticum monococcum) and often confused with spelt (Triticum spelta), but early forms of wheat and how and when they were domesticated is so complicated that even today with DNA analysis it's not completely understood. Although a reliable crop, emmer never yielded as much as other grains, including the barley (krithari) and durum wheat (sitos) that gradually replaced it.
Emmer is high in magnesium, fiber, protein and vitamins and very low in gluten (which clogs nerve endings and makes them 'sleepy'; some people even say the ancient Greeks were so clever because they ate so little gluten!).
The Italians, notably in Tuscany, have never stopped planting farro as it's called in Italian, and in recent years Greek farmers have joined them, marketing it as Δίκοκκο σιτάρι (Dikokko sitari). The nutty grains are good in a soup, or biscuits; you can also buy it made into flour or pasta.
Images by mpaxarika.gr, PD