Jerusalem Artichokes are an awesome perennial that can get over 9' tall. I've read that this plant is usually somewhere between 4-9' tall. It is native to the eastern parts of the United States (where I live). They are related to sunflowers and have really pretty yellow flowers. Like sunflowers, they may need staking in really windy areas (like my place). I'm planting mine along the south facing length of the rabbit shed to provide some summertime shade for the buns.
People can eat the underground tubers which others say taste like water chestnuts if eaten fresh and potatoes if cooked. I've read that they are sometimes called fartichokes- thinking this is fairly self-explanatory.
Rabbits can eat all parts of this plant, which makes me really excited! I'm hoping to (eventually) grow enough to make a significant dent in the rabbits feed bills. Be aware that this can be a really invasive plant and almost impossible to get rid of. Make sure it's planted where you want it to be in 20 years.
These are fairly expensive tubers and I was lucky enough to be given some from a homesteading friend- TYTYTY Farmerwilly2!!!!!!!!!!!!!!!!!!