Posts Tagged ‘paleontology’

On the Persistence of Ferns

July 7th, 2009 | Meera

On an early January day in Chicago this year, my muscles twitching in protest of the cold and the sky around me bright with winter sunshine glancing like arrows off the curves of strangers’ sunglasses, I stepped into the Fern Room of the Lincoln Park Conservatory to warm my face with the humid breath of the forest primeval.

If you have never had the pleasure of visiting the Fern Room, the best way I can think of to describe it is to tell you that it is a place where all the colors of the spectrum seem to have been suddenly replaced by a hundred thousand different shades of green. The light that outside was so harsh and dazzling is now filtered through shady fronds of emerald, jade, and olive, and instead of walls and corridors the stout trunks of cycads and the lacy leaflets of ancient ferns divide the room into secret passages and broad arcades. At every turn you begin to expect a horned triceratops or armored ankylosaurus to push through the vegetation, shaking its head and crying, What—is it you? For shame, for shame! You’re sixty million years early!

I came for the cycads, having just read of the endlessly charming Oliver Sacks’ journey to a remote Pacific Island in order to run his hands along their stiff, glossy, blade-like leaves, beguiling but toxic suspects in his search for the source of a strange disease of the mind. But it was the ferns that captured me. I liked their delicately forked fronds, each one divided into innumerable leaflets, called pinnae, that spread outwards like gentle fingers touching the air. Some curled this way and that, and when they did I could see that they were studded with neat lines of rough buttons on the underside. The buttons were called sori, I learned later, and each little nub of a sora held clusters of sporangia, themselves tiny round bubbles holding even tinier spores—these last, as fine as dust, the powder of the next generation.


In the time of Shakespeare, people didn’t know about spores. They thought it obvious that ferns, like all other sensible plants, propagated themselves through seeds, which are eminently practical devices that contain not only the embryonic beginnings of a new plant, but food for the road as well, and have smooth, smart coats to protect them from the elements. (Spores, which are single-celled motes almost too small to see, seem impoverished by comparison.)

But since, five hundred years ago, not a soul had yet recognized the brown patches on the undersides of fern leaves as containing reproductive particles, it began to be believed that the so-called seeds of ferns were cryptic, secret things, not simply well hidden but, in fact, invisible. And like spores that fly far from the fronds where they were first exhaled, that idea traveled and grew. Eventually, wondering herbalists transformed it into the astonishing claim that if you could, somehow, collect the elusive fern seed (say at the moody hour of midnight on Midsummer Night’s Eve) and clutch it in your hand, you yourself would be veiled from the prying eyes of others. In the words of a thief from Henry IV, about to embark on an ambitious robbery, we steal as in a castle, cock-sure; we have the receipt of fern seed—we walk invisible.

It is a very pretty notion indeed, but if I were to steal an essential quality from a fern it would not be invisibility, but persistence.

It isn’t easy to contemplate the earth in its wildest, most wonderful days of youth, but when we do picture it, ferns are the plants we see in our mind’s eyes, blanketing the new world in a riot of green fronds and settling their wispy roots into a rich black soil. The very oldest of ferns are almost impossibly ancient, at least from the perspective of complex living things, some 345 million years old; that makes them older than the dinosaurs, older than flowering plants, and far older than any fuzzy bee that they might otherwise have relied upon to pollinate them. They were giants, then, too, snaking up to the height of ten-story buildings. After the dinosaurs dwindled and died, and almost every other form of life went with them, ferns returned first of all to make the earth verdant again. They grew close together, like brothers, and shielded the soil, and gave other green things the time they needed to revive.

Not only old, ferns, not only huge, not only tenacious, but also numerous: their tally during the Carboniferous period, when they first appeared, was so great that when they died, their remains helped to form vast coal beds all across the earth, hundreds of miles wide and hundreds of feet deep. For hundreds of years we have mined the bodies of ferns to fuel our industry, build our cities, and sustain the needs and desires of our daily lives, and still we have not managed to exhaust their reserves.

What is perhaps even more astonishing is that throughout all these long eons, many ferns have continued to unfurl, generation after generation, into the very same forms they have always had, altering very little about their strange, self-sufficient design. Soft brushes wielded by eager paleontologists, for instance, have gently pushed the dirt from two hundred million year-old fossils of Osmunda clatoniana. Today, the same fern continues to put forth its long, fuzzy stalks in rich woods from Newfoundland to Manitoba, South Carolina to Arkansas, and every point in between.

Its common name may be the “Interrupted Fern,” because tiny brown leaflets, fertile with hundreds of thousands of spores, break up the smooth green lines of its fronds—but its lengthy existence on this earth has been anything but. The same answers that made sense to it two hundred million years ago still make sense now: it has the same leaflet shapes, the same reproductive mechanisms, the same root systems, the same way of throwing up a circlet of fronds from a single central spike, as if fashioning a fringed fan with which to stir the air around an ancient deity.

"A small dinosaur would feel at home...

Consider the stubbornness, the sheer dogged tenacity, of those two hundred million years, against these other figures: the species lifespan of the average flowering plant is only about 3.5 million years—a blip of a figure that closely parallels the species lifespan of the average mammal. Having reached that ineluctable expiry date, most living things give up the ghost, hand over their space on the planet to some newer, upstart species better suited to the planet’s changing circumstances.

Consider this: our own species, even with all our long history of literature and progress and scientific endeavor, and despite the fact that we have been around long enough to dream delightful dreams about fern spores and invisibility and awaken to learn that they are false, still, Homo sapiens has only had a mere five hundred thousand years, give or take a couple of hundred thousand, to work on its routine.

Two hundred million years, and how much more than we has the Interrupted Fern already seen? How much will it witness, after we are gone? How it must yawn, to look upon the petty wars and conquests of human affairs. How wise it is to stay so long the same.

I am not like the ferns. I have spent my thirty years on changes and modifications, constantly refashioning my own shapes, mechanisms, and systems in the hope that there is, after all, a better answer. I have been shy as often as I have been bold; I have worn the crown of ambition as often as the mask of nonchalance; I have copied friends and enemies, believing their shapes an improvement over my own. I have been myself a dozen different ways, and still never found the right one. I am trying out a new incarnation right now, in fact—fingers crossed that this time I know what I’m doing—if only you could see me shift.

I admit that I am tired from all this transmuting. I long for those two hundred million, long to stretch like that. Long to peer out beyond the glow of my own small candle flame and gaze at all that has come before and all that will come after. I am hungry for the peace that I imagine must accompany such a lingering existence.

human contact

And yet, you know, the funny thing about it all is that when your thumb is as inky-black as mine, the lives of plants seem fleeting and fragile.

I once killed a succulent, those hardy green survivors that—like camels—hoard water within their fleshy parts for dry days, by deciding that the most logical place for it was atop a radiator in December. There it baked and shriveled and, inside two weeks, limply relinquished its grip on life. Growing things beyond number have expired under my care, littering my past with inglorious remains: basil; rosemary; cilantro; narcissus; aloevera; bamboo. Just this afternoon I was re-potting six tiny transplants, baby tomatoes and strawberries grown from seed by a friend with more verdant talents—and even as I gazed upon them tenderly, a faint, funereal voice seemed to whistle past my ears: Poor things, it sang. They’ll be gone before the summer’s out. Every pot on my back deck is a memento mori, a reminder of the impermanence of all things.

But there are different measures of longevity. By one, the meandering lifetime of a human gardener, seventy or eighty years long, stretches out like an eternity, punctuated by the small gasps of scores of individual plants that unfurl and pass away within a season in yard after yard, home after home. By another, the entire collective lifetime of the human species is but a gasp itself—at least when compared with the persistence of ferns.