Encyclopedia of Earth
Encyclopedia of Earth: Ecology: Lichen
Article describing the different categories of lichens, their physical features, how they reproduce, their evolution, and important benefits lichens provide to humans. (Published: July 19, 2010)
Palomar Community College District
Wayne's World: Desert Varnish and Lichen Crust
Lichens thrive in common and in very specialized and inhospitable climates. This clickable index site offers text and photographs of desert and mountain lichens.