The two groups may overlap and are not fully distinct. This species is the 2-rowed barleys with a tough rachis. The central spikelets all contain a fertile flower, while flowers in the lateral spikelets are either male or sexless. The deficiens group, with lateral flowers containing no sexual parts. Hordeum irregulare E. Aberg and Wiebe.
Central spikelets contain fertile flowers and set seeds.
A number of species of Hordeum are native in various parts of the world. None of the native species is in cultivation. Barley plants are annual grasses which may be either winter annuals or spring annuals. Winter annuals require a period of exposure to cold in order to produce flowers and set seeds, thus are planted in the fall. They form a rosette type of growth in fall and winter, developing elongated stems and flower heads in early summer.