Two-row barley (Hordeum distichum). Watercolour artwork illustrating stages of growth of two-row barley. The stem at left is topped by spikelets of flowers, arranged on a raceme. The stem at right shows the development of grains, the weight of which has forced the spikelet to hang downwards. Two-row barley is the oldest cultivar of wild barley and is suitable for brewing due to its high enzyme content. However it does not have the high protein content of six-row barley. All barley is a good source of vitamin E, and the minerals calcium and iron.