A large herbaceous perrenial plant, native to Eastern Asia. It has hollow stems making it appear similar to bamboo, however it is in no way related. The stems can reach 3-4m in height every growing season. The leaves are green oval, and truncated at the base and it forms creamy white flowers on 6-15cm long racemes (wikipedia 2006)
This plant is every garden owners' worst nightmare. The botanical version of the bubonic plague. So much so that in the UK it is illegal to plant (under the wildlife and countryside act 1981).
If you cut it down, a new plant can re-grow from a segment of stem only a couple of centimeters long and the roots go deep into the ground. Because of this most domestic waste sites WILL NOT accept it, and it has to be taken to an incinerator, treated as hazardous waste.
If you find Japanese knotweed, there's not much you can do
1, spend your next 10 pay-cheques on specialists to remove it
2, try cutting it down yourself, burning the plant completely as you go, and dumping whatever herbicides you can get your hands on all over where it was and hope!
3, build a bonfire on top of the patch..and incinerate it
4, move house and let someone else deal with it
japanese knotweed...yeah...you want how much? fuck that, i'm moving