As you enter the arboretum at the White Oak Pavilion, one of the most noticeable features in the landscape is the lichen covering the trees, such as, the Oregon white oak and the Oregon ash. It feels like that If you stood in one place for too long, lichen might start growing on you.
Lichen is the combination of two organisms. It is part fungus which is known as the mycobiont. It is part green algae and/or cyanobacteria which is the photosynthetic organism known as the photobiont. The more I read about lichens, the more complex this partnership (mutualistic symbiosis) seems to be. Basically the fungus is able to obtain food that is produced through photosynthesis by the photobiont. The green algae or cyanobacteria benefit from the fungus by being protected from the environment, for example, to keep from drying out.
One that is particularly eye-catching is the curtains of Fishnet lichen hanging in the trees. They have a lobed structure that resembles a fishnet.
There are more than a 1000 lichens growing in the Pacific Northwest (Oregon, Washington, British Columbia and Alaska)!
