Wondering about Reindeer Moss

Although reindeer don’t live in Ohio now, it was a different story during the last ice age.

About 24,000 years ago the Wisconsinan ice sheet expanded into Ohio. Central Ohio was buried under 1000 feet of ice (305 m). Near Lake Erie, the ice was five times thicker. As the ice sheet expanded southwards, all forests in its path were ground to a pulp. Animals from Canada gradually moved southwards, as did plants and other organisms. Since the ice sheet only covered two-thirds of our state, the unglaciated, southeastern portion of Ohio became a habitat for reindeer. But reindeer didn’t stop at Ohio’s southern border. Because of the colder climate, they moved far into the south. For instance, Mark Gelbart has published an interesting article about Caribou (Rangifer tarandus) in Pleistocene Georgia.

And this is where my small part in the story begins. I was hiking the rim trail of Conkle’s Hollow (described previously) when I came upon this unusual plant.

I had never seen anything like it before. So after photographing it, I tried searching the Internet for “white moss,” and I soon encountered something called, “Reindeer Moss.” Since it’s really a lichen and not a moss, it’s also known as “Reindeer Lichen.”

As you might have guessed from the name, this lichen is an important part of the reindeer’s diet, especially in winter. It’s very high in carbohydrates, but it’s so low in protein that reindeer eat animal products to balance their diet, such as eggs or even small mammals.

I also learned that there is an Ohio Moss and Lichen Association. Their web site is a bit difficult for the novice to navigate, but it appears that in Ohio we have five varieties of reindeer lichen. The two species that seemed to most closely match my specimen were Cladonia uncialis and Cladonia rangiferina. The site said that the first one is found on the rims of sandstone cliffs in southern Ohio, and that describes the setting for the lichen in my photo. The second variety is supposed to grow in dry soil in southeastern Ohio which also describes the locale where I found mine. However since I am an amateur when it comes to lichens, let me know what you think.

There is an interesting Wikipedia article on the second variety of reindeer moss, Cladonia rangiferina. According to this article, people can eat it, too. Apparently you dry the lichen, crush the dried material, and then make a porridge out of it. I hear it’s good mixed with berries. Or lard. Or fish eggs. Okay, maybe with berries it wouldn’t be too bad. At any rate, I’m making a mental note of the recipe in case I have to forage food from the forests after the zombie apocalypse happens. Or could it be that I’ve been watching too many episodes of the TV series, The Walking Dead?

Actually it seems like it would be a shame to harvest any reindeer lichens. They only grow 3 to 5 mm a year. However if they aren’t gobbled up, they can live 100 years.

If you are new to lichens, you may not know that a lichen is two organisms in one. An individual specimen is approximately 90% fungus and 10% algae. The fungus portions provides moisture, minerals, and structural support. The algae contributes photosynthesis. Although these two organisms are genetically unrelated, neither can exist without the other. This made me curious as to how the species reproduced. This is what happens. The lichen forms little balls of fungal material (soredia) which enclose and protect several algal cells. Then the fungal balls are released into the air much like spores. If a fungal ball is lucky enough to land in a suitable habitat, both the fungus and algae begin to multiply. At this point the lichen is well on its way to establishing itself.

So that’s what I uncovered in my research. But here’s where the “wondering” comes in. I have read that when the ice sheet of the last ice age retreated, it left behind little mini-habitats in Ohio that resemble those found in Canada more so than the surrounding Ohio countryside. Within these odd, Canadian-like habitats, relict species from the ice age live on. So I found myself wondering if reindeer moss is an example of such a relict species. In my imagination, both reindeer moss and reindeer moved south as the ice sheet advanced. As the climate warmed the reindeer retreated northwards, but pockets of reindeer moss were left behind.

At any rate, I’ve been unable to confirm that’s what happened. I’m still curious though, and I welcome your thoughts.

Additional Information

• TrekOhio: Overview of Hiking Trails in the Hocking Hills
• TrekOhio: Hocking County Parks & Nature Preserves
• TrekOhio: Airplane Rock — this post includes more photos of Reindeer Moss