Here is a dry grain of barley, also known as a barleycorn. The barleycorn is an English unit of length equal to 1/3 of an inch, such that 3 dry barleycorns laid end to end make one inch. The grain in the picture along with four others from the same bag averaged 0.252 inches, a bit short of the standard. Barley is the fourth most grown cereal grain in the world, behind maize, rice and wheat.
Equipment used: Canon EOS Rebel T5i with a standard zoom lens (EF-S 18-55 mm) on a 49 mm long extension tube.