Creeping thistles (Cirsium arvense) otherwise known as Canada thistles or California thistles are fast-growing and spreading ...

Invasive thistles in Central Washington include: • Canada/creeping thistle (Cirsium arvense) commonly found in lawns, gardens and disturbed areas. It has a waxy green leaf and a formidable rhizo ...

Blackgrass, an annual grass that is non-native to Ireland, has been designated as a noxious weed for the first time.