I still have horrible, horrible memories of trying to root that stuff out of my back yard in Boston. Every time Kriss or I would pull on a stalk, it would lead down to this thick, bulbous, pulsating knob-like root 3 or more feet underground, which when it finally came up had obviously broken off from a yet deeper root system. We eventually realized that the entire yard had been invaded (and indeed was nearly completely comprised by) a single plant.

I'm glad in the abstract that it's edible, but I would fear it colonizing my intestines.