I need help in trying to get rid of this plant (??) . If you know what it
is, it tends to spread by rhizomes and I am presuming that if you keep
cutting down the growth then it will just keep spreading to "grow". I also
presume that if one "plant" was left this might cease the rhizomes from
spreading.

However, what I really want to do is get rid of it completely. Any
suggestions?