1. Barley | Cereal Grain, Hordeum vulgare, is an edible annual grass in the family Poaceae grew as a cereal grain crop. It is a tall grass with a hairy stem that stands erect and produces spikelets at the head. The stem is made up of nodes and internodes. The internodes are solid, whereas the internodes are hollow. 2. What is Barley | Cereal Grain and its uses? Barley is a cereal grain. People often eat grain as food. Some people also use grain to make medicine. Barley is most commonly used for heart disease and high cholesterol.