Barley (Hordeum vulgare subsp. vulgare) is an annual self-pollinating diploid grass. It originated in the Fertile Crescent, was the staple food of the Roman gladiators (the hordearii), and arrived in the Americas in 16th century. There are multiple classes of barley with the main distinguishing features being: Row Type(20row vs. 6-row), Hull Type (hulled vs. hull-less), Growth Habit (spring, facultative, winter), and End Use (malt, food, feed). Based on the spikelet arrangement, barley can classify into two-row or six-row. Two-row barley is commonly used in malting since the higher malting extarct yield.