It is easy to forget that our modern cereal crops were developed from wild varieties of common grasses. It is when one finds a grass and then identifies it as wild oat (Avena fatua) that this is brought home. Even though the family resemblance is there the wild and the cultivated oat differ in many ways and although related it does not take much wild oat to grow amongst cereal crops to cause problems in harvesting.
Wild oat has very delicate spikelets on fine stemmed branches, several (five or six) emanating from hubs at intervals along the central stem. The spikelets are covered in fine, silky hairs. The sheath-like leaf comes at the bottom of the stem. Flowering from June until September it can be found quite frequently in the corner of arable fields and on waste ground.