blasted knotweed
Look what a beautiful, horrible wretch this is!
Here this is a cursed swallower up of waysides and waters. It grows in dense stands of nothing but itself, choking out all others. Its roots resist dying by any means. When it is cut, each node that so much as touches the dirt sets roots of its own. And each of these florets will become a seed packaged in a papery sail, millions on millions blowing hither and yon.
You can eat the young shoots like rhubarb. I've always wanted to pickle them.