Cow Parsley (Anthriscus sylvestris), also known as Wild Chervil, Wild Beaked Parsley, and Keck, is a herbaceous biennial or short-lived perennial plant in the family Apiaceae, genus Anthriscus. It is also sometimes incorrectly called Motherdie (especially in the UK), however Motherdie is actually a name for Crataegus monogyna. It is native to Europe, western Asia and northwestern Africa. In the south of its range in the Mediterranean region, it is limited to higher altitudes. It is related to other diverse members of Apiaceae such as Parsley, Carrot, Hemlock and Hogweed.
The hollow stem grows to a height of between 60-170 cm, branching to umbels of small white flowers. Flowering time is mid-spring to early summer. The tri-pinnate leaves are 15-30 cm long and have a triangular form. The leaflets are ovate and subdivided. Cow Parsley grows in sunny to semi-shaded locations in meadows and at the edges of hedgerows and woodland. It is a particularly common sight by the roadside. It is sufficiently common and fast-growing to be considered a nuisance weed in gardens. Cow parsley's ability to grow rapidly through rhizomes and to produce large quantities of seeds in a single growing season has made it an invasive species in many areas of the United States. The state of Vermont has listed cow parsley on its "Watch List" of invasive species while Massachusetts and Washington have banned the sale of the plant. (Description from Wikipedia).