Mealy Shadow Lichen
Where to Look: Begin this tour by the ramp between the Monte L. Bean Life Science Museum and the Museum of Art (MOA). This first lichen is found on trees. Begin at the bottom of the ramp, and head south along the sidewalk until you hit the second tree along the path. Be sure to look along the base of the tree.
What is a Lichen?
"A lichen is not a single organism. Rather, it is a symbiosis between different organisms - a fungus and an alga or cyanobacterium." (From the Australian National Botanic Gardens)
Pin-Cushion Sunburst Lichen (blue)
Hooded Sunburst Lichen (red)
Scrambled Yolk Lichen (pink)
Where to Look: These three lichen are all found clumped together on the same tree. Following the same path at the bottom of the ramp, continue to the fourth tree. Notice the differences in colors, each new color is another lichen!
So now you know that lichens are actually a symbiosis of multiple organisms, but what exactly does "symbiosis" mean? According to the Merriam-Webster online dictionary, symbiosis can be defined as "a cooperative relationship." In lichens, the fungi (known as the "mycobiont") and the algae and/or cyanobacteria (known as the "photobiont(s)") cooperate together in what some believe is a "mutualism," or an association in which both partners are benefiting from the relationship. But are lichens really so amiable?
Tree Shadow Lichen
Where to Look: Following the same path at the bottom of the ramp, heading south, continue to the seventh tree.
Lichen-Forming Fungi: The "Dominant Partner"
The fungal partner in a lichen symbiosis is said to provide the lichen with the majority of its recognizable characteristics, from its shape to its fruiting bodies (United States Forest Service). In fact, in the scientific world, the name of each lichen is really just the name of its fungal partner!
Maritime Sunburst Lichen
Where to Look: This lichen is found between the ASB and the MOA. It is found on a tree directly east of the lightpole (shown in picture).
Algae and Cyanobacteria: The Photobionts
Lichens do not take any nutrients from the materials they grow on, so what gives them sustenance and energy to survive? The fungal partner isn't able to produce its own food, and so the lichen depends on the algal partner. Algae are able to produce sugars internally using only sunlight through photosynthesis, and the fungi uses those sugars to live and grow. In this sense, the lichen-forming fungi "cultivates" the photobionts, controlling their growth, exposure to sunlight, and reproduction, in order to feed itself. Because of this interaction, it has been said that lichens are really just "fungi that have discovered agriculture." (Trevor Goward)
Maritime Sunburst Lichen....again
Where to Look: This lichen is found on a maple tree west of the HFAC. The tree is north of a red fire hydrant. Be sure to check the base, right at soil level.
So what's in it for the photobiont?
If the lichen symbiosis is really so one-sided, with the algae being held in the fungi's suffocating grasp, constantly working to sustain a partner who doesn't seem to give anything back, why doesn't the photobiont just call it quits? Well, if it indeed had a choice, perhaps the algae would pull the plug on this relationship. On the other hand, however, it's possible that the photosynthesizing algae actually do benefit from remaining committed to this relationship. Not only does the symbiotic association with the lichenized fungi provide the algae with optimal living conditions, but their population is likely larger within the lichen than it would be outside. It has also been claimed that the photobiont probably "benefits from improved access to mineral nutrients which are provided because of fungal digestion outside their cells." (the British Lichen Society)
Arguments can be made for both sides--maybe the lichen symbiosis is more of a controlled parasitism than a mutualism, or maybe the photobionts are happier and better off in their associations with their fungal partners. Either way, lichens have managed to maintain and recreate these relationships time and time again. And as we might expect, not every relationship looks the same...
Hammered Shield Lichen
The Four Forms of Lichens
The basic structure of a lichen (called the lichen thallus) can be categorized as one of four forms: Foliose, Fruticose, Squamulose, and Crustose (UCMP Berkeley)
A foliose lichen looks "leaflike, with flat sheets of tissue [that are] not tightly bound." (UCMP)
Dotted Ramalina Lichen
Where to Look: Trees east of the WILK, near the round-about.
A fruticose lichen is recognized by its "free-standing branching tubes." (UCMP)
Fruticose lichens are pretty rare in the Intermountain West. In fact, most of the lichen species you will see on the trees east of the Wilkinson Center are not normally found in Utah, and you might notice that most of them are looking fairly dry and worn. So how did they get here? These trees came from nurseries in the midwest, a more moist and humid environment that supports some species of lichen which would not survive well in the dry heat of our home state. Here in Utah, these lichens won't last long. But while they're still visible, we are able to enjoy a variety of lichen species that we normally wouldn't be able to see!
Where to Look: This lichen is found on the trees east of the WILK, near the round about.
The Lunar Rim-Lichen is made up of small disc-like structures. When you look this closely, you will notice a variety of brightly colored lichens. Some Native American cultures used lichens to dye their fabrics!
Ring Firedot Lichen
Where to Look: Head to the stairs west of the Maeser Building. This lichen is found at the top of the stairs on the concrete balcony. Check the south railing to find this exact shot!
Squamulose and Crustose Lichens
To finish up our discussion of lichen forms, we will describe the last two forms: squamulose and crustose lichens. Whether you realize it or not, these lichens are the ones you're most familiar with. Next time you're going to a friend's bonfire party up Rock Canyon, or wandering along the Slate Canyon trail, take a look at the rocks around you. "Squamulose and crustose lichens dominate [the] Great Basin" (St. Clair et al.) and once you know what to look for, you'll realize that these little guys are everywhere!
Hoary Cobblestone Lichen
Where to Look: Stay on the concrete stairs west of the Maeser, but go down the stairs to the balcony. This lichen is found all along the railing, and can be recognized by its white color.
Squamulose lichens look like "tightly clustered...pebble-like units." (UCMP) Sometimes they blend right into the rocks they establish on!
Stonewall Rim- Lichen
Where to Look: This lichen is found along the same railing as the Hoary Cobblestone Lichen
Crustose lichens, as their name implies, look like a thin layer of crust. They grow so tightly against their substrates that you can often rub your hand across the stone and not feel the difference between the rock and the lichen!
Where to Look: From the balcony, head north down the paved trail. This black lichen is found on the concrete wall to the east of the walkway!
See if you can find this Keyhole-shaped crustose lichen on the stone wall!
This lichen, along with the next one, was not identifiable. The field of lichenology is full of exciting discoveries to be made! Unidentified lichens like this one abound, and new species are being discovered all the time!
Where to Look: This yellow lichen is found along the same concrete wall. This lichen is very large and easy to spot!
So now you know the basics about these amazing organisms growing right here on campus! You may not have noticed them before, but now you'll be able to recognize lichens everywhere you go. The world is full of things to discover! Maybe you will be the one to officially describe these unidentified species of lichen, and BYU campus will be the home of a lichen named after you! We hope that after completing this walking tour of the lichens of BYU campus, you can say with us, "I'm likin' lichens!"