What is Reindeer or Caribou "Moss?"

Reindeer moss (Cladonia rangiferina) is a kind of plant very frequently seen along public roads at the edge of a woods. Actually, it can grow in alpine regions to as far south as Florida. It grows on the surface of the ground. What makes it stand out is its distinctive gray-green color. When driving by a patch of it, I like to point it out to my passengers. Some of them want to see it up close, so I pull up and stop for them to examine it. When I tell them it grows without roots they are amazed. How can it grow without any roots?

Reindeer Moss: What isn't It and What is It?

Reindeer moss isn't actually a moss at all-it's a lichens. Well, what is a lichens? A lichens is a form of fungus (usually of the class, Ascomycetes) that grows in a symbiotic relationship with algae. Thus, a lichens isn't actually simply one plant, but two, cooperating together for the benefit of both. The fungus part is called the mycobiont. It serves as the substrate for the alga, thus providing stability and a measure of protection from the elements. The unicellular green alga supported by the fungus is named Trebouxia erici. Since it produces the food for the lichens through its chlorophyll, it is termed the photobiont. An image of this alga may be seen on the Botanical Society of America website.

Reproduction

Interestingly enough, the lichens called reindeer moss can generate spore producing structures (such as that of soldier moss) that reproduces the fungal part of the lichens, but not the algal part. Reproduction of the lichens is more complex. Lichens spread via two structures involving clusters of cells, namely soredia and isidia.

Behavior During Dry Spells

Lichens may lose water to become completely dehydrated, without dying. In fact, during such spells, lichens become very brittle. When once water becomes available again, the pieces re-hydrate. Pieces broken from dehydrated plants establish themselves as new plants.

What Uses is Reindeer Moss Known to Serve?

Reindeer or caribou moss was named after its usefulness as animal fodder in its alpine ranges. Reindeer moss is also valuable as a soil builder. Reindeer moss contains various nutrients and chemicals that make it valuable. It is high in carbohydrates, as well as in Vitamins A and B. It may also be used as a thickener. Since it is so sensitive to pollution, it can be used in environmental tests for air purity. Lichens such as reindeer moss may serve as sources for certain phenolic chemicals once thought to exert an anti-microbial action on soil bacteria.

References and Resources:

University of Florida, School of Forest Resources and Conservation - Florida Forest Plants - Reindeer Moss

University of South Carolina, School of the Environment - Reindeer Moss

University of California at Berkeley, Museum of Paleontology - Lichens: Life History & Ecology