As a companion to the Fungi thread http://photography-on-the.net ...read.php?t=1351534&page=1.
Lets see all your Lichen's, close-ups, abstracts, environmental, there is a lot of variety is the lichens themselves and where they grow.
Please no fungi like mushrooms and bracket fungus.
A lichen is a composite organism that arises from algae and/or cyanobacteria living among filaments of a fungus in a symbiotic relationship. The combined life form has properties that are very different from the properties of its component organisms. Lichens come in many colours, sizes, and forms. The properties are sometimes plant-like, but lichens are not plants. Lichens may have tiny, leafless branches, flat leaf-like structures, flakes that lie on the surface like peeling paint, or other growth forms.
Above from the Wikipedia Entry
Here is some starters.
Bearded Lichen on trees
A flat example
On a statue