Did you give or receive flowers for St. Valentine’s Day? Though not a flower, your commercial floral arrangement may have included our local native sword fern.
Ferns were considered magic for a long time — during the Middle Ages in Europe, for example, eating a “fern seed” was believed to make you invisible. Perhaps it’s true: when was the last time you saw a fern seed?
Seeds are how many plants reproduce, of course, and are usually the product of sexual reproduction.
In sexual reproduction, organisms split their genetic code material in half, sending their halves out (or making them available) to combine with the code-halves of others of their species. We call the packages of code-halves egg & sperm in animals; ovule and pollen in flowering plants. The two halves combine to result in an entire set of genetic code for a new individual. In flowering plants, this new individual starts as a seed.
Ferns don’t have flowers or seeds, but they do engage in sexual reproduction. Look on the underside of a sword fern leaf in spring and summer and you’ll see rows of small spots, called sori. Each spot (sorus) is packed with tiny spores, packets of the genetic code halves.
Some of the huge numbers of spores shed by the fern in late summer will find a suitably damp spot to germinate. The dime-sized plant that grows from the spore has only half the genetic code. Such “haploid” (referring to the half of the genetic code) plants are called gametophytes (“guh ME tuh fites”).
The fern gametophyte develops into a somewhat heart-shaped structure with tiny rootlets at the pointed end and microscopic reproductive cells across the flat side. If there’s enough water, the fern “sperm” will swim to nearby fern “eggs” to combine.
The combination, now with the complete genetic code, develops into what we recognize as a fern with characteristic upright fronds. This phase is called the sporophyte (“spore uh fite”), because it will again produce spores.
So, instead of flowers, ferns and their relatives use an entire, separate body in the process of splitting and recombining their genetic code.
Common in our woods, sword fern (Polystichum munitum) is the hardy, upright fern with little “thumbs” on each leaflet. The thumbs look rather like the hilt on a sword, hence the name.
The Oregon Coast is home to about a dozen other common ferns. Bracken (Pteridium aquilinum) is the very tall, wide-leafed fern. Each bracken frond is divided several times into what look like branches, twigs, and leaflets. The sori, when present, form a rough line just inside the inner edge of the leaflets. Spreading widely by underground stems, bracken ferns can pop up in surprisingly dry sites, such as in open sand.
Deer fern (Blechnum spicant) produces two kinds of fronds. Rising out of the central clump at an angle or parallel to the ground, the sterile fronds are flat with wide leaflets. Standing straight out of the clump, the fertile fronds are slightly folded in the middle with narrow, crimped leaflets. The sori are packed tightly down the centers of the narrow leaflets on the upright fertile fronds.
The fan-shaped maidenhair fern (Adiantum pedaum) thrives only in the dampest spots, such as beside waterfalls and rivulets. The rhizomes of licorice fern (Polypodium glycyrrhiza) snake beneath the moss on trees, sprouting fronds along the way. Leathery polypody (Polypodium scouleri), with its short, blunt fronds and few, large leaflets, lives only in trees at the sea’s edge.
While most of us value ferns today for their beauty and wildlife values, the first people of the Southern Oregon Coast found them much more useful. According to Patricia Whereat Phillips, author of Ethnobotany of the Coos, Lower Umpqua, and Siuslaw Indians, the people cooked and ate the rhizomes of bracken fern, drank beverages made from the rhizomes of licorice fern for pleasure and for medicine, used the shiny black stipes of maidenhair fern to decorate baskets, and layered the especially tough fronds of sword fern for covering or padding and tied fronds together for temporary walls—among other uses of these remarkable plants.
Our tougher fern species are out and green through the year, but the bracken and maidenhair shrivel back in winter. Both tough and tender ferns will send up new fronds through the spring, each arising tightly curled, like the head of a fiddle — a “fiddlehead.”
Soon will be the time to start looking for fern fiddleheads on those romantic walks in the forest.
For information on how you can arrange your own exploration of our fascinating natural history, contact Marty at firstname.lastname@example.org, www.facebook.com/wavecrestdiscoveries, or by calling 541/267-4027. Questions and comments about local natural history are welcome. www.wavecrestdiscoveries.com