Fiddlehead ferns are not a particular species of fern. Instead, the term “fiddlehead” refers to the young plants of a variety of fern species, which produce distinctively coiled fronds. These fronds resemble the scrolls -- or decorative headstocks -- of violins. Although most fiddlehead ferns contain toxic compounds, you can still eat the ferns safely in small quantities. People commonly boil fiddleheads or eat them raw in salads. The taste of a fiddlehead fern is reminiscent of asparagus.
Ostrich ferns (Matteuccia struthiopteris, also M. pensylvanica) are native to the eastern United States and grow in upright clumps that can reach 5 feet tall by 2 feet wide. According to Fine Gardening, off all the fiddlehead fern varieties, ostrich ferns are the most popular for culinary applications. The large fronds, or leaves, of the fern are pinnate, which means that each frond consists of several smaller leaflets or pinnae arranged on either side of a central stem. During the middle of spring, the fronds of the ostrich ferns unfurl, producing the fiddleheads. In autumn, these fronds droop and lose their scroll-like shapes. So if you are planning on eating the fronds of these fiddlehead ferns, which are the edible portions, you should do it while the fronds are at their freshest; before they begin to droop. Like all ferns, the ostrich fern does not produce flowers, fruits or seeds; instead, it reproduces through releasing spores. The ostrich fern thrives best in shady, moist environments.
While the fiddleheads or young edible fronds of ostrich ferns are typically light green in colour, the fiddleheads of cinnamon ferns (Osmunda cinnamomea) can be bright, brownish-orange. According to the University of Wisconsin, the fertile or spore-producing fronds adopt this cinnamon-like colour, changing from their usual green, in the late spring or early summer. More specifically, the cinnamon ferns in northern states mostly change colour in June, while in southern states they may change colour in late May. Unlike with other types of fern, the sterile fronds of the cinnamon fern are drastically different from the fertile fronds. In addition to remaining green, the sterile fronds are much larger, sometimes reaching nearly 5 feet long. Both the fertile and sterile fronds of the cinnamon fern are edible, provided they have developed into fiddleheads.
Native Americans have been using the fiddleheads of the bracken fern (Pteridium aquilinum) as a food source for centuries. In addition to boiling and consuming the actual fronds of the young plants, they more frequently ate bracken-fern rhizomes. Rhizomes are the underground stems or shoots of ferns that grow out laterally. According to the University of Florida, Native Americans would prepare bracken-fern rhizomes by drying them and roasting them, and would sometimes steam them as well. In addition to eating them separately, the Native Americans would bake the rhizomes into bread. Like the cinnamon fern, the bracken fern thrives in moist, slightly acidic soil.