Avena barbata is a species of wild oat known by the common name slender wild oat. It has edible seeds. It is a diploidized autotetraploid grass (2n=4x=28).[1] Its diploid ancestors are A. hirtula Lag. and A. wiestii Steud (2n=2x=14), which are considered Mediterranean and desert ecotypes, respectively, comprising a single species.[2] A westie and A. hirtula are widespread in the Mediterranean Basin, growing in mixed stands with A. barbata, though they are difficult to tell apart.