Gotta Love Lichens

If you visit the Academy this time of year, you’ll learn how important lichens are for reindeer (or caribou, as they’re known here in North America), especially in the winter when there’s little else to eat. Beyond reindeer, though, lichens find little love. Unless you find yourself talking to the Academy’s Anne Barber. The subject seems to come up regardless of the conversation. “Lichens are crazy awesome organisms!” she lets everyone know.

Why, you might ask. (I did ask.) Several reasons, according to Barber. Lichens often get lumped into botany, but they’re not plants. They’re actually fungi that photosynthesize, she explains. They reproduce via spores like other fungi, but they involve a symbiotic relationship among two separate organisms. Within the fungus body are algae or cyanobacteria, which do the photosynthesizing, providing the fungi with nutrients. Some say it’s not symbiosis, Barber says, and that the algae are slaves to the fungi. But how else could algae grow prolifically in the desert (than as part of lichen), she asks.

And she has a point. These organisms can tolerate any sort of harsh environment, live in most ecosystems, and are found on every continent, including Antarctica. They’ve even survived space, Barber likes to point out. They have a few tricks up their sleeves (well, maybe not sleeves) to survive extreme conditions: UV protection on their surfaces, and in incredibly dry conditions, lichens simply go dormant, then completely regenerate when conditions are more humid or damp.

Survival is serious business for lichens. They are some of the longest-lived species on our planet. Fully mature lichen can be 100 years old, or even older! They grow super slowly, Barber says, three-to-five millimeters per year. So the bigger patch of lichen you see, the older the organism is! Next time you see a lichen, do the math.

Still not convinced lichens are crazy awesome? They grow on plants, soil, rock, bark, plastic, and one species even grows underwater in freshwater. One or two species are vagrant and simply blow around in the wind like tumbleweed. They’re also very visually diverse—some look like mosses, some tiny flowers, some don’t even resemble a living thing. Most are very small and easy to miss, Barber says, but once you start noticing, you’ll see lichens everywhere.

But don’t eat them, she cautions. Unlike reindeer and a few insects that eat lichens, they are terrible tasting and we need to boil them for digestion. Some Native Americans used lichens medicinally, but for the most part humans (and most animals) leave them alone, except as occasional bird nest materials.

So lichens—crazy awesome survivors, right?

Image, reindeer moss (Cladonia): Bien52/Wikipedia