Avena fatua is a species of grass in the oat genus.

This oat is native to Eurasia but it has been introduced to most of the other temperate regions of the world.

[2][3][4] A. fatua is a typical oat in appearance, a green grass with hollow, erect stems 1 to 4 feet (0.30 to 1.22 m) tall bearing nodding structures – panicles – of spikelets.

The long dark green leaves are up to 1 centimetre (0.39 in) wide and rough due to small hairs.

This species and other wild oats can become troublesome in prairie agriculture when it invades and lowers the quality of a field crop, or competes for resources with the crop plants.