what are lichens?

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Biology textbooks tell us that lichens are alliances between two organisms—a fungus and an alga.
New discovery changes that.

I  of IV: Corals of the Forest

You’ve probably walked past them hundreds of times. Devil’s matchstick, frog pelt, lungwort, and, of course, fairy barf. While these sound like ingredients for a fictional witch potion, you can find these and more on a walk through the forests of British Columbia. Let us introduce you to a symbiotic relationship like no other—the lichens.

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II of IV:  historically linchen were algae and a fungi

Historically, lichen had been categorized as an algae and a fungi. But by constructing extremely detailed images of over 16,000 specimens, Wheeler and his colleagues at the University of Montana have been able to more accurately describe the complexities of these organisms. In reality, they are structured like “a little greenhouse,” Wheeler says.

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III of IV: What's in a Lichen?

For 150 years, scientists believed lichen were defined by a symbiotic relationship between a fungus and algae. The fungus provides structure and support for the organism, while the algae produces food through photosynthesis. However, researchers recently discovered that certain lichen have an additional fungus in the mix. This threesome was revealed after a team set out to explain what made one type of lichen toxic versus another that was seemingly identical.

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IV of IV: studying lichens

Lichens grow abundantly on the surface of rocks, trees, and even man-made objects. This video set explains the unusual biology of lichens, show their astounding diversity, and profile the field research of Harvard mycologist Anne Pringle.