The tightly curled fists of young ferns pushing through the forest floor mark a brief, tender, delicious phase in the plant's life cycle -- before the "fiddlehead" has unfurled into fronds. Snap a dark green stalk and taste. The crunchy texture and mild flavor similar to asparagus or okra make them the perfect counterpoint to all kinds of seafood and vegetables. This is why baby ferns have long been popular with native people throughout Asia and the Pacific.
In the Philippines they are called pako and eaten with patis (fish sauce), bittermelon leaves and tomatoes. Japanese call them warabi, prized in certain regions as a simple salad with other mountain vegetables.
Ancient Hawaiians collected fiddleheads, or ho'i'o, from upland forests and ate them with 'opae (freshwater shrimp), or salted salmon after salmon was introduced by Europeans. Nowadays, ho'i'o is often combined with hokugai (clams) or even canned sardines or anchovies. In places like the Hana Coast, where the ferns are abundant, they are still a staple at local lu'au.
In Asia and on the Mainland, fiddleheads are usually cooked, but in Hawai'i they are boiled only briefly to loosen the tiny hairs and improve the color and texture.
The Hawaiian species -- all of them called ho'i'o or pohole (on Maui) -- are enjoying wider popularity with the interest in traditional Hawaiian foods and Pacific Rim cuisine. The HawaiiDiet author Terry Shintani, M.D., who helps local folks shed pounds and cholesterol, and lower blood pressure while filling up on heart-healthy foods, includes ho'i'o in his popular cookbooks. And the ferns have been appearing on the menus of some high-profile Hawai'i chefs. A number of commercial farmers on Maui and the Big Island have been working to popularize ho'i'o and even export it to high-end restaurants on the Mainland.
Among the most ancient plants on Earth, ferns contain surprisingly high levels of iron, vitamin C and beta carotene. Two ounces of the raw shoots (about a half cup) satisfy a third of the adult daily requirement for vitamin C, 15 percent for iron -- nearly twice as much as spinach -- and the same level of vitamin A. They also have small amounts of calcium and the B vitamins, plus a trace of protein. And like all leafy greens, they contain virtually no fat and are high in fiber.
Look for them in farmers' markets and occasionally in supermarkets -- their short shelf life of two to three days makes it difficult to stock ho'i'o regularly until more people start buying it.
The term ho'i'o can be used to refer to a dizzying number of species difficult for non-experts to tell apart. These include the native Diplaziums sandwichianum and arnotti, the Athyriums meyenianum and sandwichianum, and even the introduced Diplazium escalantum, a native to Asia and the South Pacific that now grows wild in Hawai'i. The plants are plentiful and can be found in shady spots in damp forest on all the major islands except Lana'i. They are especially plentiful on the Hana side of Maui and the Hilo side of the Big Island.
You can try gathering fiddleheads yourself in forested areas like the Tantalus or Manoa Falls trails in Honolulu. Stick to stream banks and shaded spots that have gotten a lot of rain. Picking the wrong fern shoots probably won't hurt you, says botanist Isabella Abbott, but might give your taste buds a nasty surprise in the kitchen.
Whether you harvest your fiddleheads from the forest or the market, look for small, firm, brightly colored stalks. Try to use them immediately, or refrigerate no more than two days. Rinse off the tiny hairs and snap off the tough ends. You can chop them up to add to poke; toss them with tomatoes, onions and seafood in a salad (try a vinegar or sesame dressing); or blanch them a few minutes and use in one of the recipes below.