Lichens, like these crustose and foliose specimens, are composite organisms made up of fungi and cyanobacteria or fungi and algae.

Symbiotic organisms, fungal farmers, and brave colonizers—lichens are the unsung heroes of nature’s food web.


At almost 5,000 feet above sea level, the apex of Spruce Mountain—the tallest point in the Allegheny range—is equal parts breathlessly beautiful and startlingly bleak. At this elevation, temperatures can plummet far below freezing and stay there until spring. Here, ice and snow howl over 300 millionyear-old rock formations for months at a time. Those plants that can tough it out often appear stunted, twisted, strange. Beauty seems rare and frivolous in a climate that can change from temperate to arctic within hours.

But one decidedly beautiful life form, the odd and underappreciated lichen, has evolved to colonize places like this. Out of about 14,000 species, more than 250 are found in West Virginia. And lichens do more than just decorate their habitats. “Lichens are very important, and that’s become increasingly recognized,” says Susan Studlar, visiting associate professor of biology at West Virginia University and co-curator at the WVU Herbarium.

The red-fruited pixie cup is so named for its splash cups filled with baby lichens, called lichen powder. Rain splashes the powder out of the cups and spreads new lichens into the surrounding area.

On one hand, lichens are trailblazers. Even in difficult conditions, like the top of Spruce Mountain, these hardy organisms can survive and thrive. They are often the first living things to colonize otherwise barren landscapes. Their activities—slowly breaking down rocks and releasing minerals, creating microhabitats and food sources, conserving moisture—make it possible for other living things to move in after them. Some species even grow inside rocks, sheltered from the elements beneath solid stone.

And they’ve done so for millions of years. Recent DNA evidence analyzed at Pennsylvania State University suggests early lichens may have paved the way for some of the first forms of higher life on Earth. According to research conducted on the International Space Station, certain species of lichens can survive the intense vacuum, cold, and solar radiation of space. “They secrete a remarkable array of chemicals,” Studlar says. Some repel water when conditions are too wet, others are defensive, and still others act like melanin, a natural sunscreen. “They can also rest and essentially shut down when too dry but will revive quickly once wetted by rain.”

Another role is ecological protection. In barren environments, lichens act as shields, preventing scant soil fertility from disappearing. “They form crusts over the soil. Tangled with algae, free-living fungi, and mosses, they form a film that holds onto nutrients and prevents erosion. Lose the biotic crust and you can lose the soil and the plant cover,” Studlar says. Some species of lichens even directly contribute to fertility, pulling nitrogen out of the air and putting it into the soil.

They are also ecological indicators. “Lichens are sensitive to air pollution and to climate change,” Studlar says—so sensitive that the National Park Service, U.S. Forest Service, and other agencies around the world use them like living laboratory tests. “Lichen diversity is a measure of pollution levels. Lichen growth-forms reveal microclimate conditions. So any warming or drying that occurs with global climate change will be revealed by lichen communities.”

This golf-tee like lichen is the trumpet lichen. Many lichen thrive in the harshest environments. They often pave the way for other organisms.

Humans have long used lichens for their own purposes, for everything from bandages to dyes to art. They are used in both modern and traditional medicine for their antibiotic and anti-cancer effects. And they also have an—undeserved—reputation as survival food. While some cultures, including the Japanese and Icelandic peoples, have learned to consume them properly, Studlar warns that without specific preparation, lichen starches can’t be broken down in human stomachs. Not to mention, “they are full of chemicals that are likely to upset your digestion and make you sick.”

Lichens are essential to many environments. Yet ask a biologist or lichenologist what they are exactly—flora, fauna, or something else—and you’ll probably get a response along the lines of: “It’s complicated.”

The confusion stems from their similarities to many other things. Lichens are frequently mistaken for parasites, because they often appear on ailing trees where leaf loss has increased the amount of light filtering down onto branches, and even mushrooms, because some lichens can form mushroom-like fruiting bodies.

Studlar says lichens are all these things and yet they are different. “Lichens are actually two or more species living symbiotically,” she says. “They are partnerships between fungi and algae or fungi and cyanobacteria.”

This common toadskin lichen is nestled among a mixture of other crustose and foliose lichens. Some lichens are so small they live between particles of rock and can only be positively identified under a microscope.

Symbiosis, a mutually beneficial and interdependent relationship between two species, isn’t rare in the natural world. Think of clown fish and sea anemones, mycorrhizal fungi and plant root systems, or even humans and their domesticated dogs. “Lichens are a remarkable model for so much life on earth,” Studlar says.

Unlike you and Fido, the species that make up lichens are extremely tiny. The larger organism you see growing is actually a composite, a partnership of necessity. The fungus partner, most often a sac fungus, or ascomycete, wants food. The alga or cyanobacterium can make its own food—sugars produced by photosynthesis—but is easily dried out or damaged.

In most cases it’s up to the fungus to initiate the pairing. With its tentacle-like hyphae, it can trap and envelop a passing alga or bacterium and feed off its partner’s sugars when it needs them. But the exchange isn’t completely one-sided. Around its partner, the fungus will build an extravagant home to protect it from dry air and solar radiation. It also provides water and minerals. “Essentially, the lichen is a fungus that is farming algae, confining the algae in a thin layer near the surface, near the light, and restricting its reproduction,” Studlar says. “When you culture the fungus by itself, it’s just a mass of hyphae. But give it algae and it starts to produce these incredible feats of plant architecture and art.”

The process of lichen growth is glacially slow, a few millimeters a year, but eventually the elaborate bodies we see begin to take shape. Meanwhile, the lichen fungus is free to reproduce—sexually with fungal spores or asexually by breaking off bits of its lichen body, fungal and partner cells intact, and allowing those bits to disperse and spread.

Crustose lichens like this sunken disk lichen adhere to rocks and form living skins. Some lichens help break down rocks and release minerals into the environment.

From carpets of green on headstones in Ireland to splashes of orange blooming on rocks in the Utah desert, lichens around the world build soil, create habitats, and add beauty to landscapes. But, Studlar believes, with West Virginia’s high mountains, foggy valleys, and abundant trees, our home state is one of the best places to see these organisms. “The fabric of life here is incredible,” she says. “Lichens make that much more visible.”

Lichens of the Mountain State

Scientists group lichens into a few categories. Among those found commonly in West Virginia, there are the fruticose or shrubby lichen, like pixie cup lichens.

There are foliose umbilicate lichens, attached to their chosen substrates at single points, like the aptly named toadskin, or Lasallia papulosa. This leathery, bubblyskinned being in shades of green and brown is often found at Coopers Rock and along the New River Gorge.

Others include examples of foliose leaf-like lichen. These are often found on rocks and trees in open woods, especially along roads and trails. Some are pale yellow or green and leave a powdery residue when brushed.

The crustose, or crust-like, lichen is possibly the most common type, though some of this variety live only between particles of rock and are too small to see. Those visible to the naked eye include Sunken Disk Lichens. Like the lichens of early times, they act as pioneer species on granite and other hard rocks, providing places for other organisms to flourish.


This story was originally published in the March 2016 issue of Wonderful West Virginia.

written by Mikenna Pierotti
photographed by Kent Mason