This video from Britain is called Hemlock Water Dropwort, Oenanthe crocata.
Translated from the Dutch FLORON botanists:
Tuesday, June 10, 2014
Hemlock water dropwort, a rare plant in western and southern Europe, is found mainly in coastal areas. Until the end of the last century, this species was only known in the Netherlands from a spot in the dunes of Voorne, where it was discovered in 1975. This place was for several decades the most northeastern known habitat in Europe.
After 2000 along the coast and inland some new areas of this species were discovered. It has recently become clear that Amsterdam, with over a hundred plants, is the largest stronghold of this species in the Netherlands.