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U.S. Forest Service

Lichen Collection and Identification


To collect lichens, first you must obtain permission to collect them from the landowner. Then it is on to collecting your specimens. It is not as easy as it sounds. Lichens grow slowly and take a long time to cover an area. You must be ethical when you collect. Please visit our Ethics and Native Plants web page for reasons to leave plants behind.

  • Just as with plants, remember, collect only lichens when you intend to use them later for identification or for adding to your collection.
  • Never take more than you need, and never take the entire population in the area.
  • Always leave some behind to recolonize the open space. If there is not enough to collect, then leave it behind. You do not want to remove the lichen from the environment completely.
  • Remember that the lichen will die eventually when it is collected and stored indoors. Lichens are alive and should be treated with care.
  • Wet the lichen first to prevent breakage during removal from its substrate. Remember that wet or damp lichens are more pliable and forgiving of mishandling.
  • When storing the lichen for the trip to the lab or for long-term storage in your collection, always use a paper bag or paper envelopes. Do not use plastic bags, especially for wet specimens. They will die quicker and turn to mush.
  • For more information about lichen collecting, please visit Harvard University, Farlow Herbarium: Lichens.

Remember that on National Forest Lands, it is illegal to collect vegetation without a permit. For collecting permit information on National Forests, please visit our Collection Permits web page.


Identifying lichens is much more difficult than identifying vascular plants. Each lichen thallus is a complete microscopic world with unique characteristics separating it from the other lichens.

Lichens are classified based on the fungus and fungal features. When identifying lichens, keep in mind that one species of fungus can have two different forms if paired with two different "photobionts". It is not common but it does happen.

lichenologist using a hand lens to identify a lichen. A lichenologist (Kerry Knudson in California) in the field using a hand-lens to identify a lichen. Photo by Chris Wagner, U.S. Forest Service.

group of botanists looking at lichens on a boulder. A group of botanists on a lichen excursion. Photo by Chris Wagner, U.S. Forest Service.

In order to identify lichen to species, lichenologists use common household chemicals and some not-so-common chemicals to test the color reaction of the unique compounds found in the structure of the lichen, as well as using a lichen key to distinguish between species. Although a few of the chemicals are common, such as bleach and iodine, others are not as easy to get and are costly and dangerous. However, just about anyone can use a botanical identification key and a hand lens to identify the genus of lichen and appreciate their collection.

Even if you are not interested in identifying lichens, they are still interesting and amazing organisms to look at with the naked eye as well as under a hand lens or microscope. Realizing the roles lichens play in our environment will give you a greater appreciation of the world around you.

Lichen Identification Links

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