Filipendula ulmaria; the meadowsweet grows on moist grounds favourable to plantgrowth. I photographed this plant in the eastern part of the Snæfellsness district at the edge of dense birch/rowan brush. It is easily recognizable because it is a rather large herb with inflorescense's of white flowers and pinnate-divided leaves. On the photo the flowers are still in bud and the inflorescence's not yet longitudinal stretched.
It is member of the rose family (Rosaceae).