Taking a Lichen to Moss

Taking a Lichen to Moss

Imagine you are out hiking. You come across a patch of fallen and dead trees in a meadow. You can smell the musk of soft, wet bark in the air. The forest is silent except for the occasional tapping of a Lewis’s Woodpecker. Suddenly, you see a tuft of hair dangling from a tree branch. You take it in your hands and feel how rough it is. Is it from a bear? A human? You turn around and see hundreds of tufts of hair dangling in the breeze; they vary from dark black to light green. What kind of animal left this?

Black Tree Lichen

What you are holding is not hair at all, but a fungus feeding with algae. When we think of a fungus, we often think of mushrooms or molds, but these organisms have distinctive features that separate them from lichen. This lichen-fungus is found all over Sawtooth country, especially in cool, moist places. These organisms are not to be confused with moss, which is actually a root-less plant that covers shady parts of the forest. While lichen-fungus, fungus, and moss are all common in the Sawtooth National Recreation Area, they are very different organisms; each with their own characteristics and modes of survival. 


There are over 144,000 known species of fungus all over the world. They are the most widely distributed organism on earth, inhabiting climates from hot deserts to the freezing tundra; some species were even found in the boiling geysers of Yellowstone. 

Amanita muscaria Mushroom 

The species includes yeasts, mildews, mold, mushrooms, and more. Some fungus can form freely in soil or water, but many form symbiotic relationships with plants and animals. Since fungi do not conduct photosynthesis or get energy from the sun, they were once considered part of the animal kingdom. However, they have since been separated into their own category. Fungus, like mushrooms, break down organic material while releasing important nutrients into the air and soil. Fungus is an important aspect in making bread, alcohol, and some cheeses; some fungi are even eaten themselves, such as truffles. One very important discovery related to mold was published in 1929 when Alexander Fleming noticed that a particular mold, Penicillium notatum, inhibited the growth of some bacterias. This led to the creation of antibiotics, specifically penicillin. Humans come in contact with some sort of fungus everyday, from bread to medicine to cheese. 

Mold in a Petri Dish


Lichen (pronounced LY-ken) is a specific type of fungus that houses algae, forming a mutualistic relationship and photosynthesizing. Like fungus, they can be found in the most extreme habitats on earth, covering about 7% of the surface of the earth. There are significantly less types of lichen than fungus, with only about 20,000 different species. Lichen can grow to become very old; some lichens are even considered to be the oldest living things on earth. This could be due to their adaptability, since they are often the first things to grow on newly exposed material, such as rocks after a landslide, as well as their ability to thrive in harsh conditions. They can survive in snow and ice by slowing growth and becoming dormant, comparable to a hibernating bear. 

Crustose Lichen

Lichen grow in many different shapes and colors. There are nine main lichen formations, from wispy and hair-like wool, to fine powder. Some lichen can even take on many different formations in one organism. The colorful crust that forms on rocks can often be attributed to crustose lichen. The color of lichen depends on the way they photosynthesize – different colors attracting different levels of sun. 

 Lichen is food for many species, especially in cold tundras where foliage is low. In these areas, animals eat the lichen that make up most of the ground cover; this includes “Reindeer Moss”, which is actually a type of lichen grown in cold climates. Humans have been known to consume lichen as well, although it contains very little nutritional value and can even be poisonous if not cooked properly. 

Reindeer Moss (Lichen)


While moss can sometimes look like fungus or lichen, it is actually a small flowerless plant. Moss often grows in clumps, forming a carpet on woodland floors. It grows best in cool, damp areas, and cannot tolerate the same harsh conditions as fungus and lichen. Moss needs a significant amount of water for at least part of the year in order to fertilize; they can dry out months at a time, but need to be rehydrated. Moss filters air by taking in CO2 and pollutants and releases clean oxygen. Moss’s carpeting growth patterns also prevent soil erosion by binding the soil on the banks of rivers and streams and stopping the soil runoff into the water. 

Pincushion Moss

Moss is often used by florists as decoration and as filler in between plants. Two notable types of moss include sphagnum and peat. Peat moss is dead and decayed sphagnum moss that is harvested from peat bogs. These mosses are often used in gardening and horticulture. 

Sphagnum vs. Peat

Fungus, lichen, and moss are all very common in the Sawtooth National Recreation Area, but they are all different species with different roles in our Idaho ecosystem. Next time you see a tuft of hair dangling from a tree or a plant growing on a rock, try to identify if it’s moss, lichen, or fungus!


Aspen Arnold is the Historical Specialist for the Stanley Museum. She loves to spend her free time jeeping the Sawtooth Mountains (on roads 4x4s are allowed) and kayaking Redfish Lake.