Ferns (Division Pteridophyta) first appeared about 350 million
years ago in the late Devonian, about the same time amphibians were
learning to live on land. While relatively primitive compared to flowering
plants and reproducing by spores rather than seeds, they have been, and
still are, very successful. They are particularly common in some marginal
environments where they may be the dominant flora, and may even become
General & History
While Ferns have been with us forever and are common in many areas, they have played only a very minor role as food for humans or livestock. This is particularly due to toxicity, the fern's first line of defense against being eaten. The varieties identified as "edible" are still toxic, but in the small amounts we are likely to eat them they don't pose significant risk to most individuals.
While many ferns are prized as decoratives, some are major pests, particularly the Old World Climbing Fern (Lygodium microphyllum) which is currently strangling large areas of the Everglades in Florida, and the aquatic fern Giant Salvinia (Salvinia molesta) which is covering entire lakes in Hawaii and elsewhere. We cannot be too bitter about aquatic ferns though, since they may have been instrumental in reversing a previous global warming episode - by covering all the lakes formed by melting ice caps and absorbing carbon dioxide. They could come in handy again for that. Also, extracts of Salvinia molesta may be effective against cancers - currently under study.Varieties
Bracken Fern -
[Brake Fern, Fernbrake; Warabi (Japan); Pteridium aquilinum]
A common fern in temperate climates, immature Bracken fronds are eaten as a vegetable in many parts of the world and particularly in Korea, Japan and parts of China. Native Americans dug up, cooked and ate the rhizomes from which the fronds sprout. These still used in Japan and elsewhere as a starch source.
Pictured are water packed and dried examples from a local Korean grocery.
The dry takes a long soak or simmer and provides an interesting but somewhat
bitter flavor, so use the water packed unless the recipe calls for dry.
Bracken Fern is toxic to livestock when a significant part of their
diet. For humans it should be cooked (simmered 10 minutes) and eaten in
moderation. One of the toxins is a thiamine inhibitor that can
cause a vitamin deficiency if consumed for an extended period. Bracken
also contains a substance identified as a carcinogen and has been placed
in the same risk category as Coffee and Sassafras by the American Cancer
Society. Study is ongoing but still inconclusive, but demographics do not
indicate a notable danger.
Ostrich Fern -
This fern, common in the northern U.S and Canada and northern and eastern Europe provides the "fiddleheads" sold in commerce. They have a flavor somewhat similar to asparagus and are a little crunchy if not over cooked. They are popular in season (Spring) where the ferns grow, but are just a curiosity in here in Southern California, at more than U.S. $10 per pound from yuppie outlets like Whole Foods Markets.
Ostrich Fern is considered safe, or about as safe as ferns get. Some people have shown sensitivity to unidentified toxins in them, but most reported incidents of toxicity are from mistaking some other fern for Ostrich Fern. Simmering Ostrich fiddleheads for 10 minutes is said to make them safe for people sensitive to them. Ostrich Ferns are reported to be free of the carcinogens and thiamine inhibitors of the Braken Fern.
Buying, Storing & Cooking Fiddleheads should be 1
to 1-1/2 inches diameter with no more than 2 inches of stem projecting
from them. They should be crisp, not limp. Refrigerated they will keep
up to 10 days but lose flavor rapidly. Rub off the brown chaff and trim
the end of the stem before cooking.