Lichens are more than only one organism, there are two in each of them. Lichens are a symbiosis of fungi and algae. They grow in many different places of the world, on stones, wood or on the ground, in hot and in cold areas. There are few places on earth, where there are no lichens. Some countries do even have their own societies working on lichens.
Some species can become up to six meters long, others that are very small, only a few square millimeters in area. But all lichens grow very slowly. That means, that some of them do only expand one millimeter per year. (There are continents drifting faster.) But in centuries, they can become very large. In Scandinavia, there are large areas covered by species called 'Iceland Moss'(Cetraria islandica) and 'Reindeer lichen'(Cladonia rangiferina).
© 2002 by Richard Burghause, Germany. All rights reserved.