Thursday, December 12, 2019


When I saw the wet bracken fern frond plastered to a rock in a small side-creek it reminded me of a fossil, like something I'd associate with dinosaurs. Although ferns are believed to have first appeared 390 to 430 million years ago, the 10,500 or so modern fern species have only been around for about 70 million years, and the earliest bracken fossils are about 55 million years old. In other words, unless they are at least 10 million years older than their earliest fossils, bracken fern may be too young to have tickled the fancy of dinosaurs.

In all that time, there is still basically just one species of bracken worldwide, Pteridium aquilinum. As a Forest Service description puts it, its long evolutionary heritage has given it time to develop excellent defenses against disease and being eaten by animals.

Bracken was so valuable in the Middle Ages that it could be used to pay rent. It made a nice hot fire, and the ash was used as a source of potash by the soap and glass industry until 1860. The rhizomes were used to dye wool yellow and to tan leather.

There is also some impressive cognitive dissonance about bracken. Continuing with the Forest Service treatment linked above, we read that:

“Western brackenfern is most commonly used today as a food for humans. The newly emerging croziers or fiddleheads are picked in spring and may be consumed fresh or preserved by salting, pickling, or sun drying. Both fronds and rhizomes have been used in brewing beer, and rhizome starch has been used as a substitute for arrowroot. Bread can be made out of dried and powdered rhizomes alone or with other flour. American Indians cooked the rhizomes, then peeled and ate them or pounded the starchy fiber into flour. In Japan starch from the rhizomes is used to make confections. Western brackenfern is grown commercially for use as a food and herbal remedy in Canada, the United States, Siberia, China, Japan, and Brazil and is often listed as an edible wild plant. Powdered rhizome has been considered particularly effective against parasitic worms. American Indians ate raw rhizomes as a remedy for bronchitis” [internal citations (and double-spaces after periods) omitted].

The dissonance is that, despite being used as food, bracken is also likely carcinogenic: “All parts of the plant, including the spores, are carcinogenic,” the Forest Service writes, “and face masks are recommended for people working in dense bracken.”

According to the National Institutes of Health, bracken is “one of the few vascular plants known to induce cancer naturally in animals…. Some human populations also eat young bracken shoots and epidemiological studies in Japan and Brazil have shown a close association between bracken consumption and cancers of the upper alimentary tract. In addition, other studies reveal that the mere presence of bracken swards represents a greater risk to die of gastric adenocarcinoma for people who live more than 20 years in such areas or are exposed in childhood.”

I've been told by wild-food foragers that it's okay to eat them in small quantities, but I don't actually find the mucilaginous consistency of bracken fiddleheads all that enjoyable anyway. Apparently the choice edible species of fiddlehead is Ostrich Fern (Matteuccia struthiopteris), which according to Wikipedia “have antioxidant activity, are a source of omega-3 and omega-6 fatty acids, and are high in iron and fiber,” but alas do not grow wild in California.

* * *