Staple cereal of the Old World of the genus Hordeum. Two main groups are recognized. Two‐row barley (Hordeum distichum) derives from the wild form Hordeum spontameum that was distributed from the Aegean through to the Hindu Kush, and is recorded as early as 7000 bc at Jarmo. Six‐row barley (Hordeum hexastichum) derives from the wild Hordeum distichum whose distribution extended from China westwards to Egypt. Modern barley (Hordeum tetrastichum) is a development of the original domesticated six‐row types. Wild barley is of hulled form with the seed firmly held in the glume with a fragile stalk attached to the ear. Domesticated barley has a stronger spike which does not break during harvesting and includes hulled forms as well as the rather easier to thresh, so‐called free threshing, naked forms.
Subjects: Arts and Humanities — Medicine and Health.