Lichen is the symbiotic combination of algae and fungii, along with a bit of bacteria thrown in for good measure. Lichens grow virtually everywhere, from the artic to deserts to tropical forests, and a lichen colony can live to be anywhere between 30 and over 4,500 years (Waleski, 2007).
Lichen is an excellent indicator of air quality as it thrives in clean air environments. Where air quality is lower, lichen acts as an air purifier by removing particulate matter from the atmosphere, presumably to it's own detriment.
In addition to providing a food source for some mammals, lichens are used by industries to strengthen and dye clothing fabrics and flavor bitter beers. Certain ones are also known to have medicinal properties.
Mosses, on the other hand are non-flowering plants that have stems and leaves, but not true roots. Their life-spans usually measure in decades. While they can survive in nearly any environment except salt water, they generally prefer more temperate locations. Mosses reproduce in a number of ways: branching and fragmentation, regeneration from photosynthetic tissues, and by the production of spores.
Some mosses are not mosses at all. Irish moss is a red alga. Beard moss, Iceland moss, oak moss, and reindeer moss are lichens, and Spanish moss is an air plant of the pineapple family (Britannica).
Be sure to zoom in (Click 2x) on a few of these photos to appreciate the exquisite details of their subjects' growth.
