i like lichens

i had no idea what to say about lichens. so i did a little googling. here are some fun factoids:

• There are at least 13,000 species of lichens living throughout the world.
• Lichens are bizarre organisms and no two are alike.
• Lichens are a complex life form that is a symbiotic partnership of two separate organisms, a fungus and an alga.
• Lichens produce their own food using sunlight energy and do not feed on the tree bark.
• Lichens cause no harm to the trees they inhabit.
• Lichens can survive the most unfavorable climatic extremes of arctic, alpine and desert regions by reducing metabolic activity for extended periods of time.
• Lichens are very sensitive to air pollution, and like canaries in coal mines, may serve as indicators of air quality.
• Lichens on healthy trees should be welcomed as likely positive indicators of lower levels of air pollution.