Japanese knotweed – Fallopia japonica is from the Polygonaceae, or buckwheat, family. Very tasty alien relation of rhubarb! Either get it when its stems are young and soft and do whatever you’d do to rhubarb, or treat it like asparagus and bend it from the tip, it will snap in the right place.
Sliced into 1cm sections and pickled it makes a great alternative to an olive for a martini.
Distribution – Ooh, terrible, evil invader! Might knock down your house and steal your children.
Be very aware that it is heavily sprayed in most places and don’t go near it if there’s any chance of chemicals. Do all prep on site and boil any waste before disposal. Don’t let bits go down the sink etc.