It is several years and many photographs later, plus a macro lens, a few books, and a couple of seminars, and I'm still learning about lichens. Here are a few answers to my questions.
A lichen is a symbiotic relationship of two living organisms. One is a fungus and the other is an algae or a cyanobacteria (a blue-green algae). Each of the life forms has special jobs to do so they both can live in the same body. The fungus (usually an ascomycete) incorporates the alga and determines the shape of the organism. It provides some protection and soaks up moisture like a sponge. But, it has no chlorophyl of its own and cannot make its own food. Fungi, on their own, have to feed on other living organisms (as parasites) or feed on the decaying bodies of other organisms (as scavengers).
Algae do have chlorophyl and can use sunlight to make food from carbon dioxide and water (the process of photosynthesis). However, the algae that live as lichens would not be able to live without protection from the elements. For instance, they may be sensitive to an excess of
| Here's the follow-up discussion on this article: | View all related messages |
For a complete listing of article comments, questions, and other discussions related to B. J. Barton's Colorado topic, please visit the Discussions page.