The mystery of mountain ferns
Identifying ferns is an entirely different process than, say, identifying wildflowers or trees. They don't display flowers, showy fruits, or bark patterns. What they do display are myriad leaf (frond) forms and highly distinctive, if minute, spore cases. Once you learn how to hone in on these features, you're on your way to identifying the 70 or so native species in Western North Carolina.
Perhaps a third of these are so unique in appearance there’s nothing else you can confuse them with. For instance, along the trail that leads down the creek from our house I’ve located, to date, 17 species: Christmas fern, ebony spleenwort, marginal wood fern, rock-cap fern, hay-scented fern, sensitive fern, cinnamon fern, maidenhair fern, New York fern, lady fern, broad beech fern, bracken, rattlesnake grape fern, blunt-lobed grape fern, rusty woodsia, fragile fern, and silvery glade fern. All but the last four are easily recognizable after initial identification.
Perhaps another third of our 70 native species are so rare or inaccessible (sometimes only behind waterfalls) that the average fern seeker probably won’t encounter them. Now comes the fun part. The remaining 20 to 25 species are similar enough in general appearance that their sori (clusters of spore cases usually located on the underside of their fronds) require examination under magnification. A 10-power lens will do just fine. The arrangement, shape, or other features of these clusters will be diagnostic as to species.
In the workshops I conduct, we first review the fern life cycle and then the language utilized in field guides for fern parts. Afterwards, we visit sites where participants can work on their identification skills, using a non-technical field guide. By the end of the day, everyone is up and running in regard to ferns.
Occasionally, a natural history book will come along that breaks new ground.
Timothy P. Spira’s Wildflowers & Plant Communities: A Naturalist’s Guide to the Carolinas, Virginia, Tennessee, & Georgia (Chapel Hill: UNC Press) introduces readers to the diverse plant communities one can seek out and explore in a systematic fashion. But the concept has never been systematically delineated in a non-technical format for the non-professional plant enthusiast. In a section headed “Plant Community Profiles,” Spira describes in some detail communities found at various elevations in the mountain and adjacent piedmont regions: spruce-fir forests, grassy and heath balds, high-elevation rock outcrops, red oak forests, northern hardwood forests, rich and acidic cove forests, spray cliffs, rocky stream sides, mountain bogs, river bluff and alluvial forests, forest edges, and others.
For example, the high-elevation rock outcrop community is described in pages 119-123 as to distinguishing features, vegetation, seasonal aspects, distribution, dynamics, and conservation aspects. Sources are cited for Suggested Reading about the community. Forty or so Characteristic Plants (trees, shrubs, vines, wildflowers, grasses, sedges, spikemosses, ferns, and lichens) are listed in a table. Six rare species one might encounter in this specific community are enumerated: spreading avens, mountain golden heather, granite dome St. John’s wort, Blue Ridge ragwort, pinkshell azalea, and three-tooth cinquefoil. A set photographs illustrates most of the plants associated with each community. two-hundred and fifty pages are devoted to Species Profiles of each of the hundreds of plants associated with the various communities. Throughout this section, the entries are packed with tidbits of information about plants, including ferns, I had never before encountered.
• I knew hayscented fern as a common species resembling lady fern that often forms dense stands. From Spiria, I learned that “Established plants spread rapidly into open areas as buds at the base of leaves develop into long, creeping, underground stems … Apparently, a dense organic mat of roots, rhizomes, and dead fronds, coupled with a dense canopy of living fronds, inhibits seed germination and seedling establishment of other plants. Chemicals such as coumarin that leach from the fronds or rhizomes of hayscented fern also have an inhibitory effect on seeds and seedlings.”
• Christmas fern fronds, which are evergreen, reorientate themselves to a prostrate position in winter so as to conserve energy during cold months. The warmer ground increases leaf temperatures, promoting photosynthetic activity during relatively mild days.
• Cinnamon ferns are called “living fossils” because the forms we see today are much the same as they were more than 200 million years ago. Individual clumps can be quite old as the fibrous rootstock can persist for years.
• Most plants die after losing more than 15 percent of their water content. Resurrection fern, which curls up during dry weather, can lose up to 97 percent of its water without irreversible harm.
Most of us don't find it absolutely essential to know the name of every plant and animal we encounter, but it is a quiet joy to know the more common ones on a first-name basis. This has been especially true for me in regard to ferns. They are, after all, our most graceful plant — things of beauty, providing forms that delight the eye and add harmony to our woodland and garden settings.
NOTE: George Ellison will teach a “Native Fern Identification” workshop for the North Carolina Arboretum from 9:30 a.m. until 4:30 p.m. on Saturday, Aug. 11. After an introductory morning session, participants will car pool to habitats along the Blue Ridge Parkway where various species can be found. Walks will be short and easy. Materials required are bag lunch, rain gear, hand lens (any household magnifier will do), and the 2001 second edition of "Fern Finder" (Nature Study Guild Publishers) by Anne and Barbara Hallowell. Copies of Fern Finder will be available for purchase at the North Carolina Arboretum. Each workshop will be limited to 15 participants. For additional information call 828.665.2492.