Tree IDs: Watching the detective, being the detective

Chris Evans, extension forester for the University of Illinois, taught a class in September in learning the steps to identifying specific trees, as he demonstrated in the field and classroom. | Dale Bowman

KANKAKEE, Ill.--Before Chris Evans led us from the classroom to the trees, he said, ``You kind of have to be a detective. Sometimes the leaves are so high you have to look at them with binoculars. When out identifying trees, you need to know if it was a planted tree. Sometimes tree identities in an urban environment are challenging.’’

Evans, extension forester for the University of Illinois, is stationed in far southern Illinois. He came Sept. 18 for a fall tree walk at Kankakee Community College for master gardeners and master naturalists.

``Before we crack the book, I will ask you to describe the tree,’’ Evans said.

The booklet was ``Tree Finder: A Manual for the Identification of Trees by Their Leaves,’’ by May Theilgaard Watts. It goes for about $6 new. For basic tree identification, it is unbelievable.

``Better to know how to identify trees, rather than memorize trees,’’ Evans said.

Accurately describing the wild world of the outdoors is a fundamental too often overlooked. In identifying trees, small details build to the conclusion. The same as for identifying a fish, insect or plant.

Prime clues for IDing trees are leaf arrangement, complexity, shape and edge; twigs; buds; bark; fruit and where growing (if naturally occurring).

``Sometimes fruit alone is enough to get you to identify it,’’ Evans said.

Bark is important, especially in winter IDs.

Some tips on tree ID seem so sensible they are easy to overlook. Sometimes, you have to check shade and sunlight leaves. A lot of bark twists as it ages. Young bark looks different than old bark.

``Challenge is when you go to ornamentals, then they screw you up,’’ Evans said. ``Stay away from hawthorns, avoid them at all costs.’’

Farkleberry is the coolest name, though Devil’s walking stick, which has the largest leaf in Illinois, is close.

As to apps, specifically iNaturalist, Evans said, ``I use it a lot because I just think it is fun.’’

Seek is a sister app less sophisticated, but quicker. I find Seek very useful.

Most of us could identify this tree as a maple, but which one. It even took the Seek by iNaturalist app several more photos, before it came up with black maple from the blowing of the underside of leaves.

``I really like the forests in Illinois, it is under appreciated,’’ Evans said.

It showed.

At one time, there was almost 14 million acres of forest in Illinois, 37 percent of the landscape; now it is down to 5 million (14 percent of the landscape). That it is up from the bottom of about 3 million nearly a century ago. That 14 percent of forested land contains 70 percent of all diversity (plants, insects, etc.)

Our forests are aging, half are over 60 years old. Our forests are mostly privately owned, more than 4 million acres are on private land.

``There is a lot of forest if you know where to look,’’ Evans said.

We have about 180 native trees, including 20 oaks and 10 hickories.

``Sixty-eight percent of our forest are oak-hickory,’’ Evans said. ``The state tree is white oak. Hickories are important for wildlife.’’

Our 20 species of oak are divided into 12 reds and eight white. White oaks have rounded lobes, lighter bark; reds have deeper sinuses, darker bark.

Ecologically there are big differences. White oak pollinate in the spring, acorns grow throughout the summer and fall that fall and germinate. Red oaks pollinate in the spring, grow a tiny acorn the whole year, then it falls off the following year and does not germinate and grow until the spring, a two-year cycle that protects against one-year weather impacts.

White oaks are used to make wooden barrels and boats because of their waterproofness. Bourbon is made in white oak barrels.

Two red oaks are odd with no lobes. Shingle oaks have big leaves with no lobes, the willow oak has small narrow leaves. Northern red oak and black oak are found in every county.

Of hickories, five of the 10 are rare, especially in northern Illinois. The shagbark hickory is the most common. If not a shagbark, good chance it is a mockernut hickory. Shellbark or king nut has the biggest fruit of any hickory. Pale hickory is endangered and the rarest tree in the state with only seven known in far southern Illinois. Road trip!

As our kids grew older, I had time to earn my Master Naturalist and Master Gardener certificates. Next aim is becoming an Openlands TreeKeeper. Their eight-day course is offered three times a year around Chicago and the suburbs. More at openlands.org/trees/treekeepers/about-the-course/.

Morton Arboretum regularly offers basic tree ID courses, including two in October. More at mortonarb.org/courses/basic-tree-id.

The Illinois Arborist Association meets Nov. 5-6 at the Tinley Park Convention Center. That will include a free IAA career fair from 1-3 p.m. Nov. 5. More at illinoisarborist.org/conference/.

``Arborists are needed, it is not necessarily just for young people,’’ Evans said. ``It is a good gig right now, there are a lot of jobs out there.’’