Wednesday, January 20, 2010

Crazy About Ferns in the Adirondacks

In the 1840s, a new fad was sweeping the British Isles: Pteridomania, the fern craze. People of all ages and social groups were flocking to forests and fens to gather ferns as herbarium specimens. Special glass boxes, known as Wardian cases and looking a lot like little greenhouses, were built to provide perfect microhabitats for these sometimes fussy plants. The desire for all things ferny took over home décor: garden benches, planting pots, wood carvings, stencils, wallpaper, plant stands, fabrics – you name it, someone one decorated it with a fern. And while this craze lasted for about fifty years, it somehow never made it to the states.

Sure, a few fern-o-philes turned up on this side of the pond, and 1895 even saw the founding of the American Fern Society (which is still active today). For the most part, however, the natural history obsessions of this country seem to have turned towards wildflowers, birds and mushrooms.

As a generalist type of naturalist, I’ve always been kind of fond of ferns. They have a delicate wispiness about them that I find rather appealing. Well, at least some do. Some ferns are rather sturdy-looking, like sensitive fern (Onoclea sensibilis). Others, like the non-native Japanese painted fern (Athyrium niponicum), sport beautiful two- or three-colored fronds. Northern maidenhair fern (Adiantum pedatum) breaks the rules by growing in an almost circular fashion. Some ferns seem to be able to grow just about anywhere and are thus quite popular in gardens (ostrich ferns – Matteuccia struthiopteris), while others are pretty reclusive, their tastes limiting them to limestone cliffs (slender cliffbrake – Cryptogramma stelleri – found only at Ausable Chasm).

Any walk through the Adirondacks is bound to turn up at least a couple ferns. In just about any wetland area you are likely to find two very common ferns: royal (Osmunda regalis), and cinnamon (Osmunda cinnamomea). And while these two really do look nothing alike, for some reason I’ve developed a mental block with them, causing me to cross-identify them most of the time. Royal fern is very open and airy, with wide-spaced leaflets, which look a lot like the leaflets of the locust tree. Cinnamon fern, on the other hand, is typically ferny in appearance, but its fertile fronds are a wonderful cinnamon color (hence the name).

Hay-scented ferns (Dennestaedtia punctilobula) have been accused of being invasive, using chemicals (allelopathy) to prevent the regeneration of other forest plants (namely trees that are valuable in the timber market). And it is true that in areas where hay-scented fern occurs, it often grows in massive solidarity with itself. I read a couple studies, however, that stated that it wasn’t allelopathy that was preventing forest regeneration, rather it was simply the aggressive nature of the plant. When a bit of forest has been opened up, the extra light reaching the ground is a godsend to the ferns. They start to grow like crazy. If deer or other herbivores come in and browse the area (deer tend to not like hay-scented ferns; they’ll browse down the other understory vegetation), the ferns send out new growing bits to fill the voids, thus increasing their reach. In the end, it is the shade caused by the dense growth of ferns that prevents the regeneration of tree seedlings, not allelopathy.

A fern that delights me to no end is blublet fern (Cystopteris bulbifera). This nifty fern (see photo above) develops little green ball-like growths on the backs of the leaves. When mature, these balls drop from the leaves and if they land in a favorable location, they produce a new fern. Ferns in general reproduce via spores, much like mushrooms, mosses and lycopodiums. Bulblet fern also produces spores, but it goes above and beyond in its reproductive duty with the additional boost is gets from its bulblets.

A couple years ago I was thrilled to find rattlesnake fern (Botrychium virginianum) along one of our trails. The three triangular-shaped leaves circle the stem, and from their center rises the fertile frond, which the namer apparently thought resembled the tail-end of certain venomous serpents.

We have a giant glacial boulder on the property that looks a lot like a huge human head, and on its top, like a green buzzcut, is a healthy population of common polypody fern (Polypodium virginianum). When I stop to talk about this fern, I love to tell visitors that at one point in time people believed that if they carried polypody spores in their pockets they would be rendered invisible. Of course, this only applied to polypody of oak, and this was during the Middle Ages in Europe, when people believed all sorts of odd things about plants. Needless to say, it doesn’t work with our common polypody.

Within New York State, all ferns but three are protected by law. Those three are sensitive, bracken (Pteridium aquilinium) and hay-scented. With these exceptions, it is illegal to collect our native ferns, not that there is probably too much worry about this. I can’t see Pteridomania sweeping the state any time soon. Even so, for those of us who are plant enthusiasts, we should limit our collecting to specimens caught on camera, or those purchased from legitimate nurseries.

Probably because ferns are not terribly popular in the ID department, there are only a handful of useful fern ID books out there. Some were written by scientists for scientists, but there are a couple pocket-type guides that make fern identification fairly easy, such as the Fern Finder by Ann and Barbara Hallowell. If you think you might like to try your hand a learning your ferns, pick up one of these guides. You won’t be disappointed.


Ellen Rathbone

Ellen Rathbone is by her own admission a "certified nature nut." She began contributing to the Adirondack Almanack while living in Newcomb, when she was an environmental educator for the Adirondack Park Agency's Visitor Interpretive Centers for nearly ten years.

Ellen graduated from SUNY ESF in 1988 with a BS in forestry and biology and has worked as a naturalist in New York, New Jersey, and Vermont.

In 2010 her work took her to Michigan, where she currently resides and serves as Education Director of the Dahlem Conservancy just outside Jackson, Michigan.

She also writes her own blog about her Michigan adventures.





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  1. Woodswalker says: