Lichens of Wisconsin | Accent on Natural Landscaping

The Bridges, a newsletter from the Natural Resources Foundation of Wisconsin, featured a good article about lichens by Jaime Kenowski. (Fall 2021)

As Dr. James Bennett, who is an emeritus professor of botany of UW-Madison, once said. “Lichens, you’ve probably spent your life overlooking them, but they’re all around us — growing on rocks, trees, and even cars, clotheslines, telephone poles, or tombstones.”

Eastern candlewax lichen (*Ahtiana aurescens*) is a Wisconsin Special Concern lichen, and is found on the bark of pine trees, but rarely hardwood trees.

Many lichens are unique organisms consisting of a symbiotic growth of fungi and algae. They grow on trees, often forming colorful and interesting patches on trunks and twigs. They grow on shaded tree trunks, but the best habitat on a tree for many lichens is on high branches where they have access to full sunlight. The lichen communities found on high branches are normally out of our reach, but they can be seen when those branches break.

Indicator of Unpolluted Air

Lichens are an indicator of fresh, unpolluted air, and they struggle to thrive in highly urbanized environments. They play a role in creating soil by breaking down rocks. Small songbirds use them for nests, and some animals, including snails, deer, and even flying squirrels, eat lichens. Like everything else in Wisconsin’s interconnected natural world, lichens are being impacted by habitat loss and our changing climate. (Bridges)

Of the 800 Wisconsin lichens, here are two – British soldiers (*Cladonia cristatella*) have red tips; reindeer moss (*Cladonia rangiferina*) are bushy.

“Our northern species are moving up and out of the state, seeking the colder temperatures they need. There are species that we can no longer find up north anymore that we know used to be there,” says Bennett. “Lichens are very sensitive, so the health and presence of lichens, or lack thereof, reflects the bigger picture health and biodiversity of an ecosystem.”

Read Eastern Candlewax Lichen (Ahtiana aurescens).

You can view Dr. Bennett’s free booklet “Common Lichens of Wisconsin” online or request a free booklet by emailing mawetter@wisc.edu.

Next time you walk in the woods, take a good look where you find the lichens, and see how beautiful and varied lichens really are.

Transmittal photo courtesy of EPA.