Nothing you can liken to a lichen

Published 9:20 pm Tuesday, February 9, 2016

By Susan and Biff Andrews

So there we were in the swamp, minding our own business as casual observers of nature one recent warm, lovely, rainy day, when we were stopped dead in our tracks by the sight of a beautiful outcropping of bright orange on the side of a tree.

It was quite substantial (about the size of your two hands put together like a fan) and spectacular! It called to us like a mythological siren — bright orange is a color that catches your eye in the sea of gray and brown that is the Dismal Swamp in winter.

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The fan-shaped layers were familiar — we have seen this shape growing on trees many times, especially on downed trees. But orange?

We figured it was some kind of lichen and looked at each other and said, “Oh, lichen would be a good topic for an article someday. What were we thinking?”

What do you get when you combine a fungus with an algae? It could be something straight out of science fiction — or maybe a lichen. Most of us take lichen for granted, if we are even aware that we have seen it.

To the casual observer, lichen are merely interesting shapes, colors, and textures to look at along a trail. At first glance they appear to be simple moss-like textures (they are not moss) or mushroom-like shapes (they are not mushrooms) growing on trees or rocks.

Rest assured, they are anything but simple. Everything about them is complex and out of the ordinary for plant life.

Although mosses and lichen are both called non-vascular plants, of the two, only the moss is a true plant. Lichens are not similar in any way to mosses except in appearance, but often they share the same spaces.

The one thing lichens have in common with other members of the plant kingdom is that they make their own food through photosynthesis.

For non-botanist types like us, reading about them is downright confusing — and otherworldly. Some scientists believe lichens are tiny ecosystems unto themselves. The stuff they are made of has been on this planet since the beginning of time.

Be advised you will need your biology-to-English dictionary handy to translate when reading almost anything about lichen — we sure did! Be prepared to be transported back to the realm of kingdoms, phylums and genuses that you learned about during ninth-grade Earth science class.

Lichens are unique in that they comprise two or more different kingdoms. Lichens are fungi that have formed a symbiotic (cooperative or mutually dependent) relationship with an algal partner.

The gist of this relationship is that lichens are a successful alliance between the fungus and the alga. They combine forces, and they both thrive as a result of their cooperation. They live as one organism, both inhabiting the same body, which sure sounds like some creepy kind of science fiction.

Only certain fungi and algae can get together. If the fungus and alga are compatible, they can make a lichen body (thallus). The alga will begin to use sunlight to make sugars or food (through photosynthesis), which will feed both the fungus and the alga.

The fungus will create a thallus or body that will house both. The fungus provides this protective home and supplies water and nutrients for colonies of algae. In return for this protection, the algae cells share most of the sugars harvested from their chlorophyll. The fungus uses these sugars as food.

Next week, we’ll explore the incredible diversity of structures for lichens. We think you’ll like it.

Susan and Bradford “Biff” Andrews are retired teachers and master naturalists who have been outdoor people all their lives, exploring and enjoying the woods, swamps, rivers and beaches throughout the region for many years. Email them at b.andrews22@live.com.