It is known as the common wild oat.

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

Wild oat (Avena fatua)

Avena fatua (Naturalised)

POACEAE Avena fatua (common wild oats)

The larvae feed on Avena fatua, Calamagrostis epigejos, Glyceria fluitans, Phalaris arundinacea and Poa pratensis.

In 1922, Cooper asserted that Jasper Ridge was historically chaparral, and cleared in the nineteenth century to open grasslands, primarily Eurasian wild oats (Avena fatua and Avena barbata).

The larvae feed on Agrostis, Avena fatua, Brachypodium pinnatum, Brachypodium sylvaticum, Calamagrostis, Deschampsia cespitosa, Festuca arundinacea, Milium effusum and Poa badensis.

Common grasses include native purple needlegrass, California oatgrass, and red fescue, but also invasives such as rattlesnake grass, wild oats, including Avena barbata and Avena fatua, brome grasses, and annual fescues.