Updated: Apr 30
Winter is a season when the prairies and the forests go dormant. Insects are mostly gone, many birds have migrated, and reptiles and amphibians are hibernating. It is quiet without the singing of birds and the chatter of insects. The sun is low in the sky and the days are short. Life takes a rest. Color also takes a rest. Gone is the sea of green from the leaves of the forests and the vibrant hues of flowers taking their turns boasting the different shades of the rainbow. Instead there are the subdued tones of winter- white, gray, and brown. To some it might seem to be a somber time and they might think of Shakespeare's famous line, "Now is the winter of our discontent."
Many, however, find winter to be a time to cherish just because of that quiet, subdued, slowed down pace. They find it a time for reflection and renewal. Winter hikes, especially in the forest, can be a time to embrace stillness and solitude, and to appreciate the winter wonderland of new snow clinging to the branches of bushes, trees, and the dry stalks of grass and goldenrod. Sometimes with just the right light bouncing off the snow and ice, it can create a wonderful display that looks like it comes straight out of a fairy tale!
But not all out there is completely at rest. Of course, tracks in the snow are evidence of many critters actively finding a way to survive even the coldest of temperatures. But some less obvious, hardy species out there just take a break when the temperature falls, but then spring right back when it rises and start photosynthesizing, collecting energy from the sun, even in the dead of winter. They feed many hungry critters during the sparse times of winter keeping some from starving. And they keep all of their vibrant colors. They are all around us but mostly go unnoticed. What are they? Lichens of course!
Here's an old story: An elderly man walked into a river above a waterfall, calmly approached the edge, paused briefly as he stood looking down, and then jumped. The bystanders were aghast and ran to a point where they could see the water churning at the base of the waterfall. After many uncomfortable moments, they thought the old man had met his end, but then finally saw him come to the surface downstream and nonchalantly wade to the river's edge. They rushed down to him and a small boy asked him how he did it. He said, "It's simple. I go down with the water and come up with the water. I survive because I don't struggle."
Some have said this story might be a good way to describe lichen (and perhaps a good allegory for many of us!). Whereas many plants and animals struggle in different conditions such as temperature, lichens are happy in a wide range of conditions, even very harsh ones. They have a wide comfort zone. Like the old man, they don't struggle. They just go down and come up with the temperature, unperturbed. Down with a drought and up when moisture returns. Down and up with most anything thrown its way. Elegant sunburst lichen was even brought to outer space by the European Space Agency and exposed to the harshness of outer space with its lack of an atmosphere and water, and extremes of radiation known to be lethal to bacteria and most other microorganisms. The lichen, however, was unfazed and was able to recover quickly as if nothing had happened when it was brought back to Earth.
Many know that lichens are an ancient symbiotic partnership between a fungus and an algae (or cyanobacteria) capable of photosynthesis. Here's the ditty to remember this- "Freddy Fungus took a "Lichen" to Alice Algae" and since then they have lived happily ever after in a "marriage" that has lasted over 400 million years!
On a recent hike around Zoerb Prairie in Hixon Forest, just before a recent snowfall, this photo was taken from just below a cliff edge that we learned in an earlier blog post, "A Journey of Millions of Years", is the St Lawrence Formation:
Note that the prairie has naturally started to grow into this recently opened space but it is dormant at this time of year. Some might say it looks pretty bleak with the browns of the dead grass and other prairie plants and the grays of the exposed rocks. But wait a minute, lets get a little closer to that cliff edge.
Aha, now there's some welcome color! Let's get even closer and get out our trusty 10x loupe and camera. Now we can see the orange splotches in even more detail:
Now we really have some color and detail to marvel at, even in the dead of winter! But, wait, which lichen is this growing so prolifically on the rocks of Zoerb? Surprise, this is the famous Elegant Sunburst Lichen, Rusavskia elegans, that made the trip to outer space! A tough customer, but also very common and kind of "elegant" and charming in its own way!
Now let's look at that rock some more.
The next lichen is white, but has a little olive color in the pod like spore producing structures called apothecia. I believe this is Granite Rim Lichen, Lecanora polytropa. Or maybe Lecanora albescens, not yet reported in Wisconsin on iNaturalist. The first photo is with a ruler in millimeters to give perspective, then an even closer view:
Note how the first lichen, Elegant Sunburst has a leafy structure, while the second is almost like a crust that was thickly painted onto the surface. These are two of the three basic types of lichen- foliose with leaf like tissues free from the surface like Elegant Sunburst and crustose with a "painted" on look attached to the substrate without other structure like the Lecanora. The third type, not shown, is fruticose which grows up or away from its substrate in more of a three dimensional form like a very small tree or bush. A couple of examples are British Soldiers and Reindeer Lichen.
Next on the rock is Sulfur Firedot Lichen, Gyalolechia flavovirescens, another crustose lichen. Firedot lichens are quite successful and widespread in North America, often seen on rocks, including gravestones in cemeteries:
The last example that was on the rock is one I believe is called False Russell Fishscale, Psora pseudorussellii. OK, it's brown, but it is a vibrant green during warmer, wetter times and is complemented by those brown lumpy looking apothecia sitting on the leafy scales and is pretty impressive growing on bare rock in the middle of winter.
Next, here are some lichens that were on some branches scattered around that had been blown down from trees:
Candleflame Lichen, Candelaria concolor, a lichen that grows on tree trunks and branches and is very pollution tolerant and therefore seen commonly in cities. It has a substance called calycin that is responsible for its yellow color and acts as a sunscreen to protect its algae partner that is light sensitive:
Next, Pin Cushion Sunburst Lichen (or maybe Poplar Sunburst?), Polycauliona polycarpa. Both of these sunburst lichens are commonly seen on tree branches and are also very pollution tolerant. In fact, they grow more prolifically around cities and agricultural areas because of the high nitrogen levels that exist from pollution and fertilizers. The orange color comes from the substance parietin which, again, protects the algae from the sun, especially UV-B radiation:
Third, Hoary Rosette Lichen, Physcia aipolia. Similar to Star Rosette but the apothecia here have a whitish haze from calcium oxalate crystals called pruina, typical of Hoary Rosette. One type of Physcia species in past was commonly found growing on human skulls. Because of a common belief in the past called the Doctrine of Signatures, it was thought that since this lichen was growing on skulls that it must be a good treatment for epilepsy. So, it was collected for this purpose and at that time was worth more than its weight in gold!:
Last, one of the most common lichens, Common Greenshield, Flavoparmelia caperata. This one can grow quickly (up to 4 mm per year which is lightening fast for a lichen) to a very large size if given room on a large branch or the trunk of a tree. It is also sensitive to air pollution and has been used to assess the air quality after remediation because it is one of the first lichens to regrow after the air improved:
So, enjoy your quiet winter hikes, but if you want a little color once in a while even in the dead of winter, stop and look carefully at the rocks and sticks around you and enjoy the smorgasbord of color emanating from the lilliputian world of lichens. You just might take a "Liken to Lichen"! Ha, ha! And maybe you'll think Mr Shakespeare should have said, "Now is the winter of our.... happiness, Made glorious by the color of lichens!"
Last, I did my best to correctly identify the lichens, but I certainly could have made some mistakes. I'd welcome any feedback. Here are a couple of references for those looking to get to know lichen better. First is a pamphlet that can be ordered free from the Wisconsin State Herbarium and has 30 of the most common lichens in Wisconsin:
It's also available at this link: https://herbarium.wiscweb.wisc.edu/wp-content/uploads/sites/205/2017/10/lichens-of-wi-web-20170515.pdf
Second is a book by Joe Walewski:
Here is a handy website for lichens of Wisconsin:
And iNaturalist is an amazing resource!