Bite-size Biomimicry: Lichen

Lily Urmann
2 min readSep 23, 2021

What can we learn from lichens about cooperation or protection from the elements?

Image courtesy Jael Vallee via Unsplash

I have been constantly fascinated by this often overlooked, yet very complex and interesting organism. It’s found in every habitat on land — from the freezing arctic to the harsh desert. In fact, lichen is an important life form in these places where other plants struggle to survive. They provide important food sources for other organisms, and create soil by breaking down rock and trapping nutrients or water.

Lichens are a prime example of a symbiotic, or mutually-beneficial relationship between two or more species. The fungi (sometimes even two species of fungi) provide the structure and “housing” for an algae (and/or cyanobacteria) which produces the food via photosynthesis. This relationship has allowed lichen to inhabit every corner of the Earth — it’s able to survive despite extreme conditions.

Different kinds of lichen have different and distinct forms. Crustose lichen grow very close to a substrate and form a crust on surfaces such as rocks — they come in vibrant colors like orange, yellow, and bright green. Foliose lichen have a “foliage”-like appearance and a distinct top/bottom — they can be leafy or convoluted and full of ridges. Fruticose lichen can be shrubby and often hang-off trees, with hair-like or branch-like appendages that resemble coral structures. Check out AskNature.org for some more really interesting functions and strategies of lichen.

You can usually tell what kind of algae a lichen has just by color alone. When a lichen is dry, its color is usually gray or colored like the fungal cells on the upper cortex. When a lichen is wet, those cells become transparent, and the algal cells underneath get a chance to show its vibrancy. These colors and structures often have a specific FUNCTION: such as protecting from temperature extremes or reducing water loss via evaporation. Colors are a byproduct of the complex chemistry of lichen tissues. If you get a chance take a look at some lichen under a dissection microscope, it’s like a little universe!

Read more about lichens here.

Watch my TikTok video exploring lichens here.

So my question to you is: what can we learn from lichen about cooperating with other species and protecting from the elements? Let me know in the comments!

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