Our native ferns: mysterious, ancient, beautiful

All plants have seeds, right? People in Shakespearian England thought so; wondering why nobody could ever find fern seeds. Surely, ferns must have seeds, therefore they must be invisible — and if you could find and hold one, you would be invisible, too! So common was this fantasy that Shakespeare wove it into the plot of “Henry IV” with Falstaff’s seemingly invisible thieves. It took another 200 years for botanists to fully solve the fern reproduction mystery. Most of us today are still mystified — we incorrectly assume that ferns grow from germinating spores.

What we miss is the hidden alternate generation lacking in flowering plants. We know the spore-producing structures — dots or lines — on the undersides of fern fronds (leaves). Tiny spores released into the air — millions from a single frond — are blown vast distances to land on moist soil. There they grow, not into a new fern plant, but into a fingernail-sized heart-shaped flap of tissue called a prothalus, upon which male and female sex organs develop. Released sperm cells swim in rainwater to the female organ; thus the reason ferns favor wet habitats. Then, from this sperm-egg union, a tiny fern with roots, stem and leaves begins to grow to complete the life cycle.

Coal from ancient ferns

Among the first land plants able to transport water from roots up stems, ancient ferns and clubmosses were trees whose remains over time became peat in warm swamps; then compressed to coal by the heat and pressure of succeeding layers above. Beginning in the 1600s, mined coal fueled the Industrial Revolution.

Native Washington ferns

You might expect that in our wet climate, ferns would abound. True, the forest floor is carpeted with sword fern, but the number of different fern species is relatively small; about 30 statewide. Summer-wet Eastern states each have more than twice as many. Our summer-dry climate lacks moisture for that sperm swim on the prothalus.

Passengers may enjoy four ferns in Gig Harbor from the car window: sword, bracken, lady and licorice. Unlike sword fern, whose fronds arise from a clump, brackens arise separately, connected underground by lateral rhizome stems. On all continents except Antarctica, bracken fern is one of the world’s most abundant plants. Elegant and graceful lady fern abounds in wet areas including roadside ditches. My favorite is licorice fern which grows as an epiphyte up on birch and maple trunks. As the mosses they grow among dry out in the summer, licorice disappears and regrows when the rains return in the fall. Licorice fern rhizomes have the flavor of the popular confection; trailside taste treats hikers learned from native peoples.

To eat or not to eat?

There is a long tradition in Europe, America and Asia of eating fiddleheads, the tender unfurling fronds of several fern species. Bracken fiddleheads are among the first fresh greens to appear in the spring. Fiddlehead salad is eaten ritualistically during the tender fiddleheads’ very short unfurling season. Canning, freezing or drying enables prolonged consumption which can be a problem. Bracken is a known carcinogen causing stomach cancer, and it also robs the body of thiamin. Edible wild foods are immensely popular, but ferns are more to be admired for their beauty than consumed. Today sword fern is popular with florists for funerals. Ever practical native peoples bundled abundant sword fern for sleeping mattresses.

Native plants, including ferns, are delightful additions to our gardens. We admire natives on hikes through forest, field and wetland; in our gardens reminders of treks afield. On public lands, of course, wildlings are all protected, but moving them in close from more remote corners of our own property, or from a friend’s with permission, adds interest and contrast among the showier flowering plants we cultivate. Local retail nurseries stock native ferns; always worth a look. Suggested reading from the Gig Harbor Library: Moran, Robbin, “A Natural History of Ferns,” Timber Press, Portland, OR, 2004. Vitt, Marsh, Bovey, Mosses, “Lichens and Ferns of NW NA,” Lone Pine Publishing, Vancouver, BC, 1988.

This story was originally published May 13, 2015 at 3:21 PM with the headline "Our native ferns: mysterious, ancient, beautiful."