These Lichen Are Likin' My Fence

The ongoing repairs to my fence have given me another opportunity for observing nature. The strange object above is a British Soldier Lichen. These were growing in several places on my fence. This is an extreme close up - they are at most only a few millimeters high.

Lichen are a symbiotic living arrangement between a fungus and an algae. The algae provides food for the fungus through photosynthesis, and the fungus provides minerals from the environment and shelter for the algae.

The lichen takes its scientific name from the name of the fungus. In this case, a Cladonia cristatella fungus is co-habitating with a Trebouxia erici algae. What is amazing is that the fungus by itself is a white blob, and the algae by itself is a green blob. Only when they are living together do they form the stalk (thallus) with the bright red fruiting structure (apothecia) on top.

This one appears to have a few white dots on the fruiting structures. I noticed this on some photos of other British Soldiers on the internet. Nobody mentioned what these are, but I have to guess they are spores getting ready to be released. The spores are only from the fungus - the "offspring" will not form lichen unless it comes across the proper algae.


This next one, I believe, is a Beard Lichen (Usnea sp.). This lichen is well known for its antibiotic properties. Before the invention of "modern" antibiotics (derived from Penicillium fungus), Usnea lichen was placed on wounds to keep them from getting infected. If you are a Lost fan and were wondering what that "stuff" was being draped on Jacob's mother's wounds, it was probably Usnea lichen.

Unfortunately I can't be completely sure that this lichen is Usnea sp. Some other lichens look similar. If you are stranded on a desert island with an open wound and you need to know for sure, apparently the trick is to break the stalk (thallus). If there is an elastic, white cord running down the center, it is Usnea. (This bit of medical advice is from Wikipedia. You might want to consult a trained ethnobotanist before becoming stranded on a desert island.)


Finally, this somewhat boring lichen is a Common Greenshield (Flavoparmelia caperata). Hey, not every lichen can be interesting or beautiful. The wrinkly part in the middle releases "soredia", which are bits of fungus wrapped around bits of algae. These will grow new lichen when they are released, as opposed to the "spores" released by the British Soldiers which grow only fungus.

One thing I can tell you about removing lichen - if you are allergic to fungus (aka mold) you should wear a dust mask. My nose is still running and I am still sneezing.

See this link for my last adventure fixing the fence.