JESSOP: Fiddleheads on Ferns Are Starting to Uncoil
Right now is an excellent time for walking in the woods. While the shrouding leaves of summer blanket the forest floor, there is a sense of quiet waiting.
During such walks, any sound or movement seems dramatic -- woodpecker calls ricochet through the clear cold air, even the scratching of a squirrel's claws is starkly audible as he climbs along a tree trunk. Winter is the time to see deep into the soul of a forest.
And, if you do a bit of investigating, it is easy to see that, though plants and trees are indeed quietly waiting, they are very much alive.
I want to tell you about one of the families of plants that are true forest dwellers, which find their niche along forest streams or nestled deep in moist shady places along a trail -- plants that never bloom yet are treasured for their beauty.
If you pause on a winter hike to take a close look at a dormant fern and carefully pull back the leaf litter, you will see the tops of fiddleheads -- plump and waiting for the lengthening of daylight and the warming of the soil. They await the spring, just as they have awaited each spring for more than 250 million years.
Ferns have been on this earth much longer than flowering plants and trees, and much longer than any land animals. The heritage of ferns reaches back to a time when plants were just beginning to live on land, more than 400 million years ago.
Though many of the earliest ferns are extinct, we have found fossils of several modern families of ferns that date back 250 million years. In this early period of the earth's history, ferns were the dominant plants, and as a result played a significant role in the development of the coal deposits we depend on for fuel.
Flowering plants and ferns have some basic similarities -- both have well-developed vascular systems that carry water, minerals and nutrients throughout roots, stems and leaves. However, at this point, their similarities end.
Flowering plants develop blooms and depend on wind, insects and birds for these flowers to be fertilized. Then the fertilized flowers produce seeds with all the genetic material for a new plant to grow and reproduce.
Ferns have a more complicated process. They do not flower. Instead, when a mature plant is ready to reproduce, it develops spores within protective patches on the underside of the leaves. When fully developed, the spores are released into the air. These spores are not complete, carrying only half the genetic material needed to produce an adult plant.
If a spore finds a suitable spot, with the right moisture and soil, the spore develops into a very tiny intermediate plant (called a gametophyte). These plants are less than a half-inch in diameter and look much like a single heart-shaped leaf, which hugs the ground.
On the underside of this tiny plant, a very interesting process occurs. Two sets of reproductive organs develop. In one section female reproductive organs produce eggs, while in another section the male organs are developing sperm.
If there is a film of moisture, the sperm cells are able to swim about to fertilize the eggs. This can occur on the same gametophyte or adjacent ones. Water is essential for ferns to successfully reproduce, hence the reason they thrive in wet places.
In essence, ferns produce an intermediate plant with the sole purpose of accomplishing reproduction. It achieves the same thing that the flowering process with seed production does in other plants.
After an egg is fertilized by the sperm, on the underside of the gametophyte, a genetically complete cell of an adult plant will begin to develop within the protection of the gametophyte structure.
There it will grow, taking over the gametophyte and becoming an adult plant capable of producing spores.
Many ferns develop little disks filled with spores on the underside of fertile leaves. A good example is found with the Christmas fern, which remains green all winter and is often found tucked in shady, moist places in open woodlands.
These ferns develop their spores on the underside of the top third of fertile fronds (a stem with leaves).
The spore cases are so thick that at first glance the leaves look rust brown on the underside. A close look with a magnifying glass, however, will reveal the clusters of disks that protect spores within.
Christmas ferns got their name for two reasons: they stay green in winter, often traditionally used as decoration during Christmas; and the individual leaves are also fancied by some to resemble the toe of a Christmas stocking.
Another beautiful fern that thrives in our region of the state provides a good example of how different the fertile fronds of some varieties of ferns can appear. Cinnamon fern is named for the cinnamon-colored, fertile fronds that develop in early spring.
The unfertile fronds are pale green, broad and lacy. The fertile fronds, however, are narrow and erect, bright green when they first appear, then turning a rich cinnamon brown as the spores develop.
These ferns are very well adapted to our region, able not only to tolerate frequent fire, but also often showing vigorous growth afterward as the spores of this fern germinate well in the mineral-rich, ash-laden soil of a recently burned forest.
Preparing to Uncoil
One of the most interesting things about ferns is that they can be planted and even live rather happily in dry, sunny or otherwise hostile places, but they will not reproduce there -- at least not from spores.
You will only find ferns growing naturally in areas that are suitable for both the survival of the adult plant and the conditions needed for gametophytes to flourish.
The amount of moisture and nutrients required will depend on the species of fern. Some species have developed other methods of regeneration. When there is not adequate moisture for gametophyte reproduction, some varieties of ferns will develop a small plant at the tip of a frond that has dipped low enough to touch the soil.
Still other ferns are capable of spreading through their rhizomes (horizontal underground stems that put out shoots). When this happens, though, the genetic makeup of the new plant is identical to the parent plant, so it lacks the genetic diversity offered with reproduction through spores.
It is March, and the lengthening of daylight is already apparent. I cannot help but think of one of my favorite children's books, "The Secret Garden," when I walk in the woods at this time of year. I can feel the excitement that those children felt as I see the very early signs of a vibrant, healthy forest nearing the end of quiet waiting. All is "wick" (alive), as Dickon would say.
The buds swell on trees and shrubs, and upon close examination, it is obvious that the fiddleheads are larger than last time I looked. They are beginning to poke at the surface, preparing to uncoil with the fuzzy green of life renewed. They are about to greet yet another year in multi-millennia of living on this good earth.
Judy Jessop can be reached at email@example.com
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