What are lichens?
Lichens are symbiotic organisms composed of a fungus (the mycobiont) and a photosynthesizing partner (the photobiont).  The photosynthesizing partner can be a green alga (around 85% of all lichen species), a cyanobacterium (around 10%), or both (about 5% of lichens).

Ray Showman 9/28/11

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