An orange lichen?

Lower Falls - 07.25.2009 - 09.33.40

I wonder if any lichen specialists frequent my blog.  If so, how are lichens categorized?  Certainly the individual fungal and green algal/cyanobacterial species are ‘clearly’ described, but are lichens themselves able to be characterized and described in the own right?  For example, if the mutualisms are usually formed between single fungal and algal species, can a particular pair be classified?  If pairs are not usually species-specific in this way, but more general lineages of either the fungal component, the algal component, or both do form more generalized groups of lichen, do these ‘groups’ behave similarly?  Would a particular group likely inhabit a vertical slate cliff in Western New York, while another likely inhabits the forest floor?  What types of adaptations in lichen groups fit these habitats?

What if this photograph isn’t even a lichen and I’m totally incompetent?

Also, what if I had just gone to the damn Wikipedia site before I wrote all that.