Like, What's a Lichen?!

Lichens are actually two organisms living together in a relationship called symbiosis. They can take many forms, but every lichen contains a fungus and an algae. The fungus provides structure while the algae produces food that helps the whole lichen survive.

Three Forms of Lichen

Although lichens are diverse, lichens can be found in three major forms: Crustose, Foliose, and Fruticose. Tap each form to explore more!


Crustose Header

Crustose lichens are thin like a crust. The lichen's edges stay flat against the object it is growing on. Crustose lichens grow slowly and some are among the oldest living organisms on earth! This form of lichen is known for growing in a wide range of colors. Can you find these colors of Crustose Lichen?


Foliose Header

Foliose lichens look like dry wavy foliage (leaves). The edges curl up away from the surface they are growing on. The leafy surface changes based on the moisture in the environment. A process called poikilohydry allows lichens to switch-off and go dormant when conditions are dry and then switch-on when moisture arrives. 

Look for dormant and active lichens on your adventure today.


Fruticose Header

Fruticose lichens are the most three-dimensional lichens. Some look like miniature fruit trees without leaves while others hang down from branches like hair. Can you find lichens that look like these shapes?

Stuck on Substrates

A substrate is simply the surface that the lichen attaches to and grows. Different lichens prefer different substrates. Tap each substrate you find lichen growing on to check it off.

Which of these organisms in NOT part of a lichen?

What kind of symbiotic relationship makes the lichen?

Which part of the lichen can produce food?

You'll be able to add this adventure to your journal once you pass the quiz. Check your answers to see how you're doing!