By Patricia Simpson

Lichenology is fascinating. It is easy to dismiss that green stuff on the trees or on the rocks, but one only needs to start looking a little harder to realize there is great diversity in the unique life form we call lichen. This observation of the month is of one of the small lichens that grow on the ground in Mission Trails: Mealy Pixie Cup Lichen. (iNaturalist page: bit.ly/2swf9xe.)

Lichens are unique because they are not plants, though they may look like it sometimes. Lichen is the result of the ultimate symbiotic relationship between algae or cyanobacteria (photobiont) and fungus (mycobiont).

So why did “Alice Algae and Freddy Fungus take a ‘lichen’ to each other?” You may have noticed that Alice and Freddy choose homes than may otherwise look unsuitable for most growing organisms: a rock, a branch, your rooftop! Nutrients may not be readily available, and lichen can’t quite hop in the car and head to the grocery store. Instead, the fungus provides shelter, nutrients and moisture for the algae and in exchange, the algae nourishes the fungus through its photosynthesis.

Because lichens have no roots and get nutrients and moisture from the air, scientists frequently use them as an important indicator for air quality. Lichens are also used as food by many wildlife species. Native Americans used them as medicine and dyes.

So next time you hit the trails, don’t hesitate to get on your knees and you might find treasures like our observation of the month. You can find out more fun facts and details about lichens here: bit.ly/2J388Lj.

— Patricia Simpson is a trail guide at Mission Trails Regional Park.