Lichen is everywhere. It grows on sidewalks, rocks, trees, roofs and undistributed soil and in frigid tundras, arid deserts and even contaminated environments.
You just have to look for it, says lichenologist and Eastern Washington University biology professor Jessica Allen.
"They're really obvious out across the landscape if you're paying attention, and then you look closer and realize you didn't even see them before you started looking," Allen says. "There are over 20,000 species and we're still describing them. We're not even close to learning [all species that] exist on the planet, let alone where they live."
Looking for lichen in the field is one of Allen's favorite research activities, and she's pretty good at it. In the past few years she's co-discovered three lichen species, two of which are named after some well-known — and perhaps unexpected — luminaries: Oprah Winfrey and Dolly Parton.
Scientists estimate as much as 6 percent of the Earth's land surface is covered by lichen. Though it's technically a member of the fungi kingdom, lichen is actually a composite organism that arises due to a vital, symbiotic relationship between algae living amongst the fungal structure itself. Lichen structures can be all different shapes, sizes and patterns, including tree-like, flat and leaf-like, powdery or flaky.
The algae living in lichen undergo photosynthesis, feeding both organisms. In turn, lichen protect the algae from ultraviolet light and help it absorb water. Other microorganisms can also make this lichen-algae symbiosis their home, like tiny worms, tardigrades and various bacteria, Allen explains.
Dolly Parton's namesake lichen is the Japewiella dollypartoniana, common name Dolly's Dots, which grows on the bark of trees in the Appalachian Mountains near where the musician grew up. On the trip leading to its discovery, Allen and fellow lichenologist James Lendemer had been listening to Parton's music on repeat, choosing to name the lichen in honor of her contributions to music and philanthropy.
The rarer Oprah's Sunshine lichen (Hypotrachyna oprah) was named because it was also discovered near the media maven's hometown of Chicago. The species notably glows bright yellow under ultraviolet light.
Both lichens were intentionally named after women because historically so very few species are, Allen says.
"We decided to name a few after not just any women, but those who've made a huge impact in the past century."
Allen has been studying lichens since she was an undergraduate biology major at Eastern almost a decade ago. She now holds a doctorate of philosophy in biology from the City University of New York, and continues to research lichen diversity, conservation and genomics.
Though it may seem like a very small and insignificant species in the grand circle of life, lichen is a critical habitat and food source for many organisms, and not just algae. It's also an indicator of ecological health and can tell us things about air quality, climate change and even genetics.
"Animals are very reliant on lichens," Allen says. "Birds use them to make nests because they repel water and are antibiotic. Large mammals use them as a winter forage; elk and deer and moose eat them in winter when there is less vegetation. Caribou [in the tundra] are completely dependent on them for a part of their diet."
Other tinier species, like spiders and insects, have adapted to hide from predators by camouflaging themselves in lichen.
The algae living in some lichens convert nitrogen from the atmosphere into an essential nutrient for plants. In arid climates, lichen growing on the soil crust helps prevent erosion. Lichen has also been, throughout human history, an important natural source of purple dye.
Scientists are able to use lichen to monitor air quality and pollution, Allen notes.
"If you go to a place and there are none — they've all died — that probably tells you something about the air quality, that it's not great," she says.
All-natural deodorant and toothpaste often contain a specific compound, usnic acid, found only in lichens. Lichen compounds are also being considered as potential new treatments for cancer, and for use in antibiotics.
In her position with EWU, which she began last fall, Allen is currently working on several lichen identification projects, including on the Palouse, at Turnbull National Wildlife Refuge and North Cascades National Park. In Turnbull alone, more than 300 unique species have been logged. Simultaneously, Allen is also studying the genetic diversity of lichens. On a recent Friday, a computer inside her office is more than 48 hours into the genetic sequencing of a sample.
As evidenced, lichens play a pretty important role in the world's ecosystems and human life. Which is why a big portion of Allen's research on lichens involves conservation efforts, such as reintroducing them to areas they've been eradicated, and figuring out how to protect those that are threatened elsewhere. Of around 1,200 federally listed endangered species in the U.S., only two are lichens, she says.
"We know that natural systems don't function without all the pieces of the puzzle, and lichens are an important part of that. Generally they are underappreciated in conservation or not considered at all, but that's something that, in my personal research and a lot of others, lichenologists are working on — to bring the importance of them to light and get them added to the same level of conservation attention as other large species." ♦
Join lichenologist Jessica Allen on a free lichen identification walk on Sunday, June 2, at 10 am, in Riverside State Park at the Bowl & Pitcher Area's suspension bridge.