Crustose rock lichen

Many lichens also grow close to the surface of rocks, tree trunks and other substrata, and are referred to as crustose lichens. There are a different types, including endolithic, endophloidic and leprose. Endolithic lichens are immersed in rocks with their bodies above the surface. Endophloidic is when they are in plant tissue. Leprose refers to crusts without a layered structure.