Look for the epiphytes living above us

  • During dry periods, resurrection ferns shrivel and turn grayish brown, looking dead, but as soon as it rains, the fern spreads out and turns green again. PAT FOSTER-TURLEY/FOR THE NEWS-LEADER
    During dry periods, resurrection ferns shrivel and turn grayish brown, looking dead, but as soon as it rains, the fern spreads out and turns green again. PAT FOSTER-TURLEY/FOR THE NEWS-LEADER

I’m guessing many of you readers do not yet know what epiphytes are, but you will if you continue reading this. Now that Fort Clinch State Park is open again (capacity permitting), Bucko and I are doing our usual, almost daily, drives through the park. And now we have been noticing and admiring epiphytes. It’s always something.

Epiphytes are plants that grow harmlessly on other plants, most usually trees, and to notice them you need to look up. When you do this along the main road of the park you will find some surprising things. The most obvious epiphytes, of course, are the strands of Spanish moss hanging from most of the live oaks and other trees along this road. Spanish moss – not Spanish and not actually a moss – is a hallmark of the Deep South. This bromeliad pineapple-relative has a long history of being used as pillow stuffing, but today it can more often be seen dried in flower arrangements and in nature and is often used by birds to line their nests. Although it is widely believed that chiggers (aka redbugs) live in Spanish moss, so you should be careful handling it, this has turned out to be a myth. For instance, a study on Cumberland Island that looked at samples of Spanish moss collected from trees and on the ground found nearly 3,300 species – mostly insects and a few spiders – living there, but did not find a single chigger.

When you are looking at Spanish moss along the park road, look at the live oak tree branches themselves. You will see another common epiphyte, the resurrection fern. During dry periods, this fern shrivels and turns grayish brown, looking dead. But as soon as it rains, the fern spreads out and turns green again – it resurrects. A nifty experiment is to take some dead-looking resurrection fern and spritz it with water every hour and see how long it takes to turn green. Amazingly, this can happen in just a few hours! When this fern is green, like most plants, it photosynthesizes and grows, but it can live dry for days, even months, with no such activity until it rains again.

For many years, Bucko and I have been admiring the Spanish moss and resurrection ferns at Fort Clinch, but recently we have been on the lookout for other interesting epiphytes. It turns out that some other surprising plants can be found growing in the tree canopy. One particularly intriguing sight is a prickly pear cactus growing on a lateral oak branch high over the road. It is visible when you drive between the fort and the turnoff to the river campground. Prickly pear cactus is a common sight in our dry coastal dunes as they are very drought resistant and can survive in harsh water limited areas. Well, one such area apparently is a small pocket of decomposed vegetation (aka soil) nestled in a depression in a lateral tree branch. We have watched this particular cactus for years and, despite its limited habitat, it continues to grow and spread downward, and even produces seasonal flowers. This always amazes us.

We recently discovered a young palmetto growing in a knothole on another tree not too far from the large dune along the main park road. It’s on the other side of the road and takes some careful spotting to find it.

Another interesting plant has sprouted in a knothole on a tree near the intersection of the main and river campground road. If you like nature treasure hunts, you can try to find these two epiphytes yourself, but I wish you luck.

And of course, there are plenty of lichens growing on live trees too. The lichens are a symbiotic combination of alga and fungi but, like the epiphytic plants mentioned here, these do not harm the tree either. Lichens come in many species, mostly only identifiable by experts, but in various parts of the world, different lichen species have been used by biologists to classify the health of certain ecosystems. I fondly remember a day spent bicycling around a major Bangkok park with my colleague, Dr. Sompoad Srikosamatara, looking at lichens on the trees. He taught his students a curriculum about urban biodiversity and together they were able to map air quality near and far from busy exhaust-filled roads by mapping the lichen species found there.

Well, the air quality seems good in Fort Clinch State Park and lichens and epiphytes are flourishing there. The next time it is not too hot to breathe, take a look for yourself and see what you can find. Even after all our years frequently driving through the park, we always find something new to admire. Stay tuned to see what we find next.

Pat Foster-Turley is a zoologist on Amelia Island. She welcomes your nature questions and observations.