These are not related to Globe Artichokes, but are the tubers of a plant related to Sunflowers. Sometimes called Sunchokes, the tubers are delicious whether used in soups or roasted.
You can reduce this by cooking slowly over a long period; or pickling. Some folk think cooking with caraway seeds, fennel or bay leaves will also help. Either way the taste is worth it! Artichokes should be kept in a cool and dark place.