Residents of New England, especially Maine, may not think these are exotic. They are a traditional vegetable dish throughout the region, occasionally served boiled, in a salad or with mayonnaise or butter. For the rest of the country, though, fiddleheads probably look more like alien appendages than a vegetable. They are actually the furled fronds of a baby fern. One reason they re so rare outside of their native regions is that they are not cultivated only harvested from the wild and so are only found locally and seasonally. Foraging for fiddleheads is also for experts only: Much like with mushrooms, not all ferns are edible and some are poisonous.They are packed with nutrients and acclaimed for their succulent flavor. Fiddleheads are full of omega 3 fatty acids and fiber, and contain twice the antioxidant quality of blueberries.