Lichen

Hiking the trails this winter, we have seen a lot of what I believe to be different varieties of lichen. The above "hair like" plant growth is a good example.  We tend to see this type most often attached to deciduous trees and very visible this time of year on bare branches.  But what is lichen?  Ever curious, I thought that I would do some research.

According to the U.S. Forest Service, lichens are a complex life form that is a symbiotic partnership of two separate organisms, a fungus and an alga. The dominant partner is the fungus, which gives the lichen the majority of its characteristics.  The alga can be either a green alga or a blue-green alga, otherwise known as cyanobacteria.

OK, but what is a fungus?  According to the experts, fungi are a diverse group of organisms that are in their own kingdom (Fungi), separate from plants. Fungi do not contain chlorophyll or any other means of producing their own food so they rely on other organisms for nutrition. They are necessary for the survival of the ecosystem around them, such as partnering with plants and trees for nutrients and survival.  Lichens represent one such partnership for fungi to gain nutrients from another organism. The algal partner photosynthesizes and provides food for the fungus, so it can grow and spread.

Is lichen a type of moss?  The answer is no. Although moss and lichens are both called non-vascular plants, only mosses are plants. Mosses are believed to be the ancestors of the plants we see today, like trees, flowers, and ferns. Lichens, on the other hand, are not similar in any way to mosses or other members of the plant kingdom.  Although mosses are very primitive, they still have plant-like structures that look like and function like leaves, stems and roots. They have chloroplasts throughout their entire bodies and can photosynthesize from all sides of their structures. 

Lichens, on the other hand, are completely different. They do not have any roots, stems or leaves and their chloroplasts are contained only in the algae on the top surface of the lichen. As you can see from the picture above, it is not uncommon for moss and lichen to grow very near each other.

Interesting!  Can you identify the growth on these douglas fir trees from last weekend's snow shoe trip - moss or lichen?

If you guessed lichen, you would have been correct.  This growth common to douglas fir trees is called "witches hair" or alectoria sarmentosa.  Aptly named don't you think?  If you have any pictures with other varieties of lichen, be sure to send them to me and we can include in a future post.

 

Comments

[Judy]

What happened to the animal, vegetable, mineral classifications when it comes to lichen? Got to be of the three cause that's what they taught me in junior high!

[Craig]

Symbiosis