Lichen series # 1 on trees

In keeping with my learning, while in isolation during the Coronovirus pandemic, I am researching and trying to identify the various lichens that I have photographed over the years. Yowzer! This is difficult to do. I currently have the following books open: Lichens of the North Woods, Lichens of North America, and Pollution monitoring with lichens. And, there is this great poster on lichens.

Common Greenshield Lichen - (Flavoparmelia caperata) is one of the most common lichens on trees. Notice the round shape it takes on trees. And, notice that it grows on many different species of trees!

Close-up view of Common Greenshield Lichen - black lower surface. It is a foliose lichen (foliose lichens look leafy with the upper surface being a different color than the lower surface.)

Fluffy Dust Lichen - (Lepraria lobificans) can look like a pale mint colored lichen. This lichen hugs the tree tightly and is termed a crustose lichen. This species is very common on both trees and rocks.

Whitewash Lichen - (Phlyctis argena) looks just like its name suggests, like paint on trees! It is a crustose lichen with a smooth, white surface.

Boreal Oakmoss Lichen - (Evernia mesomorpha) is found on both trunks and branches of a variety of trees. It is a fruticose lichen which means that it has a bushy or shrubby growth. It tends to grow in sunny sites and is tolerant of pollution. This means that you will also find it in cities.