Vulpia myuros
Vulpia myuros, the annual fescue, or rat's-tail fescue, is an annual grass species of the genus Vulpia. It was probably originally native to Eurasia, but it can now be found nearly worldwide as a naturalized species.
In the United Kingdom it forms dense, even swards of fine, hair-like stems in recently disturbed habitats, such as 3-10-year-old pulverised fuel ash. It is typically displaced by perennial grasses after about a decade.Invasive species
Vulpia myuros is considered a noxious weed and invasive species in places where it is not native, especially in areas with a Mediterranean climate. For example, it is widespread in California, where it is now a dominant species in many types of grassy habitat.