Sunday, December 2, 2012
A late fall walk in the woods provides fewer distractions: no wildflowers, no colorful leaves, no snakes, no turtles, no frogs. Birds can be easier to see, since they can't hide in the foliage, and squirrels are very visible as they build their winter nests and harvest seeds and nuts. My attention was also drawn to some lower-profile flora-- the lichens.
On a recent walk at the Sarett Nature Center, I noticed a group of trees with interesting displays of lichen on their branches. I snapped a few pictures and figured I could identify them when I got home. One branch was covered with the cup-topped stems of the lichen's fruiting body, which I thought would make it simple to classify.
Lichens are composite, symbiotic organisms that combine a fungus and an algae (or a blue-green algae). The fungus provides the physical structure and the algae provides the ability to photosynthesize. They can grow where regular plants can not survive and they take many different forms.
My problem came when I tried to identify the lichen; Michigan has over 800 kinds of lichen and I quickly got overwhelmed. At first, I thought the fruiting bodies matched a picture of Pixie Cup lichen but then I found that many other lichens have similar structures. Then I realized that in some photos I had multiple different lichen growing alongside each other. A Harvard webpage on identifying lichens provided this advice: "By far the best way to start identifying lichens is by attending one or more workshop, course, or field trip led by an experienced lichenologist. It is hard to pick up identification skills on one's own and easy to get onto the wrong track, so beginners should seek help in getting started."
lichen photos on Steve Sharnoff's webpage.