Wherever stable and reasonably well lit surfaces occur in nature, so will lichens. A bizarre partnership of fungus and algae, lichens will grow on soil, rock, and even trees. Although they give the appearance of being parasitic on their vegetative hosts, lichens are anything but, being self-reliant in feeding themselves through photosynthesis in their algal cells. The algae, in turn, benefits from the ability of the fungus to better find, soak up, and retain water and nutrients.
Did You Know?
Thomas O. Selfridge, captain of the USS Cairo, commanded three boats which sank during the war. Each began with the letter "C"-Cumberland, Cairo, and Conestoga. The coincidence was noted after the Conestoga sank, and Selfridge was assigned to the USS Osage, which survived to the end of the war.