What’s that green stuff?

13 years ago

By Natalie Bazinet
Staff Writer

CARIBOU — With snow mostly melted and spring greenery not yet in its full budding bloom, it’s visually obvious that many trees in the area are covered by a wispy green growth. The question begs to be asked: “What is that green stuff?”

According to Forrester Dave Rochester of the Maine Forest Service, that “green stuff” is a lichen called Old Man’s Beard that can be found throughout many parts of the state.

“If the other fungi are nature’s recyclers, lichens are nature’s pioneers,” Rochester said. “Lichens find their home in some of the most barren and inhospitable parts of the world. From there they slowly begin the process of creating a foundation for habitation by others.”

In Rochester’s opinion, lichens are among the most fascinating organisms on the planet. Their structure is a unique symbiosis of two organisms — fungus and algae — that’s so complete that it behaves and looks like an entirely new being.

Lichens can literally eat stones, survive in severe cold and remain dormant for long periods of time without harm, according to Rochester.

“Lichens consist of an upper part of interwoven fibers related to the fungus and a layer of more loosely fibrous structures related to the fungus that surrounds the algae,” he explained. “The algae can carry out photosynthesis and feed the fungi; the fibrous structures that make up the fungi gives support to the algae and helps prevent the algae from drying out.”

Who would have thought that such a small, stringy looking growth would be so complex?

The lichen is also pretty useful not only as a snack for the wildlife that eats it but also for humans.

According to Rochester, the lichen was used medicinally for years due to its usnic acid content. (Usnic acid being a potent antibiotic and antifungal agent found in most lichens). With the hairline structure of Old Man’s Beard, Rochester mentioned that the lichen was also used to treat surface wounds when sterile gauze and modern antibiotics were unavailable.