Last week, I had a rare visitor; my mom! She flew into Savannah, all the way from Texas, to experience a touch of Georgia life. We had fun ghost hunting in an old brewery, went aboard a Dutch sailing ship, and she met the St. Catherines Island lemurs. I’ve known mom longer than anyone else in my life (I’m counting the time I spent in the womb) and consequently, it’s hard to avoid thinking about the past when we get together. I sometimes feel like I’ve lived many lives. When I think back to how my life was years ago, it’s almost like remembering a story I heard about another person. I think it’s good that I’m always changing; being recreated again and again, sometimes from ash.
There’s one plant on the island that might understand this feeling more than the others, could the two of us converse. It’s called Pleopeltis polypodioides, otherwise known as the resurrection fern. It lives life as an epiphyte, clinging by way of a wiry rhizome to the sprawling oak trees. When the weather is dry, the resurrection fern will shrivel up and turn brown, losing up to ninety-seven percent of its moisture. It can stay this way for nearly a hundred years, crispy and ashen, until it rains again. Then, like a proverbial phoenix, it soaks up moisture, plumps up its fronds, and becomes a beautiful green blanket, laying thick on the tops of the oak branches. It’s quite the inspiring bit of flora.
Even though it grasps trees and rocks to grow on, it asks for no more than support. No water or nutrients are stolen, no intrusion is made into phloem or xylem, and no disease or insect pest is introduced by the fern. It simply needs another plant to hold onto. It doesn’t even distract bees or butterflies with showy flowers, as it has no flowers at all. Like other ferns, it reproduces by way of spores. On the underside of each four to twelve inch frond, the fern has spore-producing structures that look like rows of dark, raised dots called sporangia (which can be seen below). When water plumps up the fern, it also washes the spores around (the whole fern reproduction process is a bit complex, so I won’t go into it here, but here’s a great site that explains it well). It’s a reproductive system that’s been around for ages.
Ferns are a form of plant called a pteridophyte (pronounced “terry-doh-fight”), which is ancient; over 350 million years old. That’s older than the dinosaurs and more ancient than all of the flowering plants. The resurrection fern is so successful that it can be found as far north of the island as New York and as far west of it as Texas, being the most widespread epiphytic fern in the United States (here’s a map). It has even been to space! In the late 90’s, scientists at the Medical University of South Carolina were looking for an organism that could survive the sometimes long storage times that precede space flight. They tried bacteria, but their specimens dried up before they could launch. It was a middle school science class who came up with the solution - a plant that can survive a long time without water and be reconstituted when the time was right. The automated water delivery mechanism and space container they came up with is quite clever (learn more here).
On St. Catherines, the resurrection fern covers nearly every oak tree and where it grows, the Spanish moss does not cling. Despite its plush carpet-like appearance, I’ve never seen the lemurs lounging in it. In fact, they seem to prefer the oaks that are free of clinging epiphytes. One oak tree that grows on the Yankee Bridge troop’s site appears completely bare in spots. This is the group’s favorite tree and they often sit in its branches to accept grapes before coming down to their food dishes. The bare patches are not only free of ferns, they’re free of bark as well and I suspect that it was once laden with ferns like its neighbors. When those branches lost their rough outer bark, the ferns were sloughed off too. Since there are no longer cracks and crevices in which fern spores can settle, no new ferns have taken hold on this tree.
I suspect that the ferns here have seen many ages on St. Catherines; many incarnations of this unusual place. Once, the island was home to the Guale people, who were introduced to the Spanish missionaries. Later, the island held plantations and freed slaves. Industry and agriculture have brought pigs, cows, oyster steamers, and lumberjacks. Much of the landscape has worn away and the glorious parrots and zebras the Foundation once cared for here have left. It’s a place that keeps changing; keeps becoming something new. Whatever might come next for St. Catherines, I hope the ferns remain to awaken again and again.