This is a winter annual grass with thin tillers (stems) growing up to 60 to 80 centimeters in maximum height, but known to sometimes grow taller. The bristly spikelets are 2 to 3 centimeters long, not counting the bent awn which is up to 4 centimeters in length. Avena barbata largely reproduces by selfing in natural populations, with very low rates of outcrossing.[1]