lichens

we observed a variety of lichens growing on the rocks.

the presence of lichens indicates a clean environment.

lichen symbiosis is a fascinating example of mutualism.

researchers study lichens to monitor air quality.

the old tree trunk was covered in crustose lichens.

lichen species can be used to identify pollution sources.

we found fruticose lichens hanging from the branches.

lichen communities thrive in harsh, exposed conditions.

the hikers identified several different types of lichens.

lichen growth rates are very slow, often measured in millimeters per year.

we collected samples of lichens for further analysis.