Wednesday, October 20, 2010

British Soldier Lichens

While I was at the Great Swamp on Saturday, I heard some insects singing in a clearing. I never did find the source of the sound, but while I was looking for the insects, I noticed some odd lichens along a log. Looking closer, I saw the red caps that marked them as British soldier lichens (Cladonia cristatella).

Despite their distinctive appearance, the lichens do not look like much from a distance. The stalks are very short, with even the tallest being shorter than than half of an inch high. That may be why I have missed these lichens in the past.

Species in genus Cladonia are cup lichens, which often grow in branching, bush-like shapes. Like other lichen, British Soldier Lichens are unions of an alga (Trebouxia erici) and a fungus (Cladonia cristatella), the latter of which provides the scientific name for the lichen. The alga photosynthesizes food, and the fungus provides structure. Lichens are very slow-growing organisms; this species only grows about two millimeters per year.

The red caps at the tops of the stalks are the fruiting bodies that produce spores for spreading the organism. A British solder lichen will produce its first spores after four years of growth. The red caps are also the reason for the lichen's common name as they are reminiscent of British army uniforms of the 18th and 19th centuries. Some guides suggest the name refers to "red hats" worn by British soldiers during the American Revolution, but it more likely refers to their red coats since soldiers of the period wore a variety of headgear, much of it not red.

Several other blogs and websites have interesting commentary on these lichens, including The Marvelous in Nature, Hiker's Notebook, and this site.