I've always thought lichens were a little mysterious. Not quite what I would consider a plant, and they look downright inert even upon close inspection, yet they are a living organism -- a fungus and an alga (or cyanobacterium) living together in a symbiotic relationship. They exist in many different forms and colors and in a wide range of habitats. I find them most surprising and delightful when I come upon them above treeline in the mountains. From a distance, bare rock looks pretty drab. But move in close, and you'll often see lichens clinging to the rock, exposed to the elements, resplendent in such gorgeous, entertaining hues as yellow, orange, soft blue and chartreuse. Another surprising thing about lichens is their ability to decompose the rock they grow on. By emitting a very weak acid, they slowly eat away at the rock; along with other erosional forces, over long periods of time they are among the forces that cause entire mountain ranges to dwindle. You'll see lichens featured on many of my other photographs, such as #0930, #0831, and #1102.