One of the most frequent questions I have heard from tree-lovers
is “What is this green stuff that’s killing my tree?” The phenomenon in question is lichen, and it
really is an amazing part of our natural world. And trust me, this is not a
tree-killer.
Lichens are those flat, often circular, slightly furry
patches that show up on your trees and, sometimes, on rocks as well.
Botanically, they are a symbiotic combination of a fungus and either an alga, a
cyanobacterium, or both, which give the organism its characteristic
blue-green-gray coloration.
At right and below, blue-green lichen grow on sugar maples
and on a Japanese maple.
Scientists, in fact, consider many lichens to be
bio-indicators of clean air, since they do not grow in areas with extreme air
pollution. Oddly, they are a food source for elk, who scrape them off rocks to
eat them. Lichens have been used for dye as well.
As with many fungi, lichens’ actual structure and life
processes were not well understood by science for hundreds of years. It was a
nineteenth-century Swiss botanist who first discovered this “unnatural”
marriage across kingdoms, although at the time of his discovery, fungi were
still considered part of the plant kingdom.
It is not surprising that these modest plants escaped
serious inquiry, since they are harmless and rarely a food source. Fungi, too,
have mysteries that have only begun to be unraveled recently. DNA research has
allowed identification of genetically identical strands of fungal mycelia
penetrating hundreds of acres, creating what some scientists consider to be
among the earth’s largest organisms.
A lecture on lichens will be presented on April 17 at the Kellogg Environmental
Center in Derby . This joint presentation by the
Naugatuck Valley Audubon Society and the CT Department of Energy and
Environmental Protection will take place at 7:30 pm, and is appropriate for
adults and children over 10. A small admission fee will be charged.
* Absolutely devoid of April Fool's content, just in case tongue in cheek humor really freaks you out!
4 comments:
Fungi can solve lots of human-generated problems too:
http://www.ted.com/talks/paul_stamets_on_6_ways_mushrooms_can_save_the_world.html
I have similar looking patches on my roof shingles (north facing). Is it possible the same stuff?
Re both Anonymous comments: Paul Stamets's TED Talk is among the best I've ever seen. His website also offers lots more info. And, yes, lichen often shows up on roofs, too,(along with moss) especially if the roof is shaded.
Lesser known fact:
most Lichens is edible, albeit they are not the most tasty veggies.
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