Thanks, There is this good sized patch of it growing outside this old (1840´s) abandoned house in southern Sweden. My husband remembered seeing it as a kid, and when we went to this old house the other day the patch was still there. He was curious what it was called. Oddly enough he doesnt think it has spread out any. Anyway thank you very much. Kari
Giant Knotweed (Fallopia sachalinense, syn. Polygonum sachalinense). An invasive weed, almost impossible to get rid of.