I always knew that a certain growth was a lichen but didn’t know much more about it until I began looking at everything on the Driftless Prairies and wanting not only to know what each item was but to learn a little about each. Working on this bio inventory has certainly expanded my world.
What is a lichen? It’s a combination of 2 things: fungi and algae or fungi and cyanobacteria.
In North America, we have around 3,600 species of lichens; worldwide there are over 14,000 with some estimates totally 25,000! They are found on soil, on rocks, and on trees, but they can be found and just about any undisturbed surface. They are very slow growing, sometimes only 1mm a year and like other slow growers, they can have long lives. They can also withstand extreme environmental conditions. UC Berkley’s website states that fossil records are hard to find but the oldest confirmed one is 400 million years and was found in Scotland.
Lichens serve a number of purposes. They provide nesting materials for birds; food for birds, mammals, insects, snails; camouflage for amphibians. It is a great indicator of air quality and helps by recycling airborne chemicals into the soil – this can be a good thing or bad thing, depending on the chemical. Lichens are used in a variety of herbal remedies; their antibacterial qualities are also being studied for use in modern medicine as they can produce up to 500 different chemical compounds. They have also been used as a natural dye.
I’ve done my best to identify these lichens accurately, seeking expert advice at times. But, being human, mistakes can happen. Please let me know if you find any inaccuracies. I’ve also used these resources for the information about the individual species as well as general info about each category.
Candelaria concolor – Candleflame Lichen
Flavoparmelia carperata – Common Greenshield
Physcia stellaris – Star Rosette Lichen
Xanthoria hasseana – Poplar Sunburst Lichen