Fiddlehead fern

Fiddleheads or fiddlehead greens are the furled fronds of a young fern,

harvested for use as a vegetable.

Left on the plant, each fiddlehead would unroll into a new frond (circinate vernation). As fiddleheads are harvested early in the season before the frond has opened and reached its full height, they are cut fairly close to the ground.

Fiddleheads have antioxidant activity, are a source of omega-3 and omega-6 fatty acids, and are high in iron and fibre. Certain varieties of fiddleheads have been shown to be carcinogenic. (See bracken poisoning)

The fiddlehead resembles the curled ornamentation (called a scroll) on the end of a stringed instrument, such as a violin. It is also called a crozier, after the curved staff used by bishops, which has its origins in the shepherd's crook.

The fiddleheads of certain ferns are eaten as a cooked leaf vegetable. The most popular of these are:

Western sword fern, Polystichum munitum, "king of northwest ferns."
Bracken, Pteridium aquilinum, found worldwide (Toxic if not cooked fully)
Ostrich fern, Matteuccia struthiopteris, found in northern regions worldwide, and the central/eastern part of North America (Health Warning)
Lady fern, Athyrium filix-femina, throughout most of the temperate northern hemisphere.
Cinnamon fern or buckhorn fern, Osmunda cinnamomea, found in the eastern parts of North America, although not so palatable as ostrich fern.
Royal fern, Osmunda regalis, found worldwide
Midin, or Stenochlaena palustris, found in Sarawak, where it is prized as a local delicacy
Zenmai or flowering fern, Osmunda japonica, found in East Asia
Vegetable fern, Athyrium esculentum, found throughout Asia and Oceania
Fiddleheads' ornamental value makes them very expensive in the temperate regions where they are not abundant.

In Indonesia, young fiddlehead ferns are cooked in a rich coconut sauce spiced with chili pepper, galangal, lemongrass, turmeric leaves and other spices. This dish is called gulai pakis or gulai paku, and originated from the Minangkabau ethnic group of Indonesia. In the Philippines, fiddlehead fern or pakô, is a delicacy, often made into a salad with tomato, salted egg slices, and a simple vinaigrette dressing.

In East Asia, fiddleheads of bracken (Pteridium aquilinum) are eaten as a vegetable, called warabi (蕨) in Japan, gosari (고사리) in Korea, and juécài (蕨菜) in China and Taiwan. In Korea, a typical banchan (small side dish) is gosari-namul (고사리나물), which consists of prepared fernbrake fiddleheads that have been sauteed. It is also a component of the popular dish bibimbap. In Japan, bracken fiddleheads are a prized dish, and roasting the fiddleheads is reputed to neutralize any toxins in the vegetable.

In Japan, fiddleheads of flowering fern (Osmunda japonica), known as zenmai (薇), as well as those of the ostrich fern (Matteuccia struthiopteris), known as kogomi (コゴミ), are commonly eaten in springtime. Fiddleheads in Japan are considered sansai, or wild vegetables.

Fiddleheads contain various vitamins and minerals, as well as omega-3 and omega-6 fatty acids. They are a source of antioxidants and dietary fibre. They are low in sodium, but rich in potassium, which may make them suitable for people who need a low-sodium diet.

Fiddleheads may harbour microbes, and should be washed and cooked before eating.

Many ferns also contain the enzyme thiaminase, which breaks down thiamine. This can lead to beriberi, if consumed in extreme excess.

Further, there is some evidence that certain varieties of fiddleheads, e.g. bracken (Pteridium genus), are carcinogenic. It is recommended to fully cook fiddleheads to destroy the shikimic acid.Ostrich fern (Matteuccia struthiopteris) is not thought to cause cancer, although there is evidence it contains a toxin unidentified as yet.