Wild Oats, also known as Avena fatua, is a grass native to Europe which is very similar to the cultivated form of oats. It grows to be a foot or two tall and looks much like its domesticated relative. Avena starts off as green in the wet season but dies off to a golden color after seeding. Avena in Europe isnt an overly abundant grass, however, about 200 years ago someone brought the seeds of this grass to California for livestock forage. The grass soon took over most grasslands and now is the dominant grass in much of California. It has been here so long that it isnt really an invasive part of the environment any more - it has pretty much reached equilibrium with the world around it. However, it has drastically changed the landscape and environment of the area, and most people who see the grassy hillsides of California dont realize that they once looked very different.