CAMPTON HILLS – Trees in winter, their bark plain with no leaves to define them, are still identifiable – if you know what to look for.
The potato chip tree is wild black cherry, easy to spot by its bark. The branches of a red oak reach to the sky while the burr oak's are crooked, the pin oak's reach down and the white oak's reach out like a wide embrace.
Buckeye, chestnut, black walnut, silver maple and basswood were also among trees that Campton Township naturalist Jack Shouba identified Saturday. Shouba led about a dozen people in a nature hike at Corron Farm in Campton Hills for a lesson in reading the landscape in winter.
"We wanted to do a little education and show people what we have here," Shouba said.
Corron Farm was part of an open space purchase that preserved 1,100 acres and 300 acres of farmland, he said. The trail through the woods at the 1830s farmstead was a blend of oaks and invasive species – like the box elder – and some like the wild cherry that are native to Illinois, but don't belong in an oak forest.
Every few steps, Shouba stopped and talked about how to identify trees in a winter landscape. Taking out a small Swiss arm knife, he cut a twig from a tree and described it.
"The twig is thick, and it has a 'face' where a leaf fell off – it's a black walnut," Shouba said, passing the twig around. From the ground, he picked up a few broken walnut shells, adding, "And there are walnuts around. That's a clue."
Another snip of another tree showed a little yellow bud. This, he said, was a yellow-bud hickory, also known as bitternut because the nut is, well, bitter.
Shouba spoke of the wonder of oak trees, especially burr oaks, with their coarse, tough-looking bark.
"That is strong enough to stand up to a prairie fire," Shouba said. "Oaks have a strategy. Their leaves burn in a fire, but their bark is not hurt by fire."
The "strategy" is survival, Shouba said. Its rivals, such as the box elder and maple trees would succumb to a prairie fire, brought on by a lightning strike. Once the rivals are swept away in fire, young oaks can sprout.
One of the challenges of the volunteers at Corron Farm, Shouba said, is to clear the understory and encourage young oaks, which need sunshine instead of shade to grow.
Areas where volunteers had already cleared more invasive species and those that do not belong, showed signs of recovery. Shouba pointed to a single clump of tall grass.
"Grass is a good sign," he said. "There is enough sun here to support it."
Greg Van Zandt, a Campton Township trustee, who attended the winter nature walk, said he learned a lot.
"I learned a lot of different things about oak trees," Van Zandt said. "I did not realize that red oak branches go up and white oak branches go side to side."
In particular, Van Zandt said Shouba explained things well.
"Jack is just so personable and brings to life the things we take for granted, like the trees and shrubs," Van Zandt said.