Well, I think somehow this thing got broken...or maybe it's intentional that it won't go away.
It says it dispelled, icon remains, timer ran down even and I'm rooted. Icon stays in the buff window.
Died and recalled and was unable to move, said I was rooted...Blighted bramble icon remained in buff window.
Shows no info if you try to get details, but mouseover says "blighted brambles."
Have to log out to be able to move.
This is very annoying.