Organic Japanese Knotweed Powder 1lb: Pure Japanese Knotweed Extract bulk for Different Uses Japanese Knotweed Root PowderKINg OF RESVERATROL: Japanese Knotweed has the highest plant level of resveratrol, part of plant compounds polyphenols which have plenty of health benefits. RIcH IN HEALTHY cOMPOUNDS: Not only it improves absorption of Vitamins..