Discovering Lichens: 3 Hands-On Activities

The activity below was contributed by Dr. Jessica Allen during our podcast interview.

Lichens are often overlooked, but these curious life forms are actually a marvel of nature. They’re not plants but a fascinating partnership between a fungus and an alga or cyanobacteria, living together in a symbiotic relationship. Lichens come in a surprising variety of shapes, sizes, and colors, and studying them can be a fun and educational way to explore the microbial world.

Here, you’ll find 3 fun, hands-on activities, ranging from simple observation to data collection, to help you discover the wonders of lichens firsthand.

If you’d like to take some time to expand your knowledge about lichens first, read the blog post about lichens based on my podcast interview with lichenologist Dr. Jessica Allen, who contributed these activities.

Activity 1: Peering into a Lichen

Materials:

• Microscope
• Slide
• Cover slip
• Tweezers
• Water
• Small piece of a lichen

Instructions:

1. Find a lichen: Go outside and find a lichen that has fallen from a tree or off of a rock. It’s best to only take lichens that are not still attached to the substrate, unless they are attached to a fallen stick or piece of bark. Let the attached lichens remain to live their full lives. For a more in-depth explanation about lichen collecting, see this post.
2. Prepare the Lichen: Using tweezers, carefully tear off a tiny piece of the lichen.
3. Make a Wet Mount: Place a drop of water on a clean slide and put the lichen fragment in the water.
4. Squish Gently: Smash the lichen under the cover slip. Be careful not to break the cover slip.
5. Observe Under Microscope: Examine the lichen under the microscope.

What to Look For: You should be able to see the fungal filaments (like spaghetti noodles) and the large algal cells (like green meatballs) living together within the lichen structure.

If you don’t have a microscope and are interested in getting one, check out my review of 6 different microscopes. If you’ve already got a microscope, but need help learning how to use it, grab my Quick Start Guide to Using the Microscope!

Activity 2: Lichen Diversity Hunt

Materials:

• Hand lens (optional)
• Notebook (optional)

Instructions:

1. Find an Area with Lichens: Head outdoors and locate a tree, rock, or even a patch of ground with lichens growing on it.
2. Become a Lichen Detective: Closely examine the area and try to find as many different types of lichens as possible. Look for variations in color, texture, and growth form (crustose, leafy, or branching – for more on lichen types, view this blog post on lichens).
3. Document Your Findings (Optional): Use your hand lens to get a closer look at the details. If you have a notebook, sketch or write down descriptions of the different lichens you find.

Fun Fact: There are over 5,000 species of lichens found in North America and over 20,000 on the planet! You might be surprised by the variety you discover in your own backyard.

Activity 3: Lichen Abundance Survey

This activity was inspired by the Great Smoky Mountains National Park activity here.

Materials:

• Transparency sheet (or clear plastic sheet)
• Marker
• Ruler
• Clipboard (optional)
• Pencil and paper (optional)

Instructions:

1. Prepare the Grid: On a transparency sheet, use a marker to draw a grid with squares of equal size.
2. Head Outdoors: Find a few trees in a similar location (e.g., all in a park)
3. Lichen Mapping: Place the grid transparency sheet against the trunk of a tree. Within each square, count the number of lichens present. You can categorize them by color or growth form for further analysis.
4. Repeat and Analyze (Optional): Perform the survey on several trees and record your data. Back home, use your data to create graphs or charts to see if there are any patterns in lichen abundance on different parts of the tree or between different trees.

Citizen Science: This activity can be a fun way to contribute to citizen science projects. Share your findings with organizations that track lichen distribution and health.