A plane tree that is not a plain tree

(This essay is excerpted from the Spring 2020 Harbinger, the newsletter of the Illinois Native Plant Society, edited by Chris Benda. Dr. Bohdan Dziadyk, Augustana professor emeritus, is president of the society's Quad Cities Chapter.)

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By Bo Dziadyk

Once in a lifetime does one encounter such a being.

It lives on a steep hillside above Mill Creek at the Josua Lindahl Hill Prairies Nature Preserve in the Quad Cities of northwest Illinois.

A small group of volunteers first noticed it when we were doing a controlled burn on the nearby hill prairie several years ago. The Lindahl Preserve, owned by Augustana College, is part of the larger Collinson Ecological Preserve dedicated to research, education, and conservation.

What makes this particular sycamore so distinctive is how it has adjusted to adversity — the hallmark of greatness in our minds. Many decades ago a heavy storm probably knocked the tree against the steep hillside so that, still firmly rooted, it was lying appressed to the soil along its entire length.

As some trees do when a living stem is pressed against the ground, the inner bark on that side was able to root and provide greater uptake of water and nutrients. Only in this case it was part of the entire bole that so rooted, allowing one large branch to take over as the primary stem and now dominating the entire growth.

The original main stem, however, continued to grow outward and upward, keeping pace in length though not in bulk, with the now massive side branch. This side branch is currently 32 inches in diameter at breast height while the main stem is only 23 inches.

I estimate the full length (height) of the tree to be some 130 feet. If the entire length were
standing upright I think the tree might be a contender for the tallest sycamore in Rock Island County and probably among the tallest in all of Illinois.

An old family

Platanus occidentalis, the American sycamore or plane tree, is a member of the ancient family Platanaceae. It has two other extant species in the U.S., and numerous fossil species have been identified.

The family is at least 100 million years old. It was thriving when the great dinosaurs were stalking the earth and survived the great extinction that eliminated them and most other life on Earth.

The sycamore is a deciduous tree growing in ravines, on hillsides, and especially along streams. It is a monoecious species whose globose fruits are sometimes eaten by squirrels when young and by birds at maturity. The seed-like achenes separate from the compound fruit in spring and float on the wind on bristly hairs. 

Botanists concede it to be the largest tree east of the Mississippi River reaching more than 120 feet in height and more than 10 feet in diameter. The tree may live for over half a millennium.

A personal history

The American sycamore was the first tree I learned as a wee lad growing up in the 1950s across the Mississippi River from St. Louis. The property next door had a large sycamore with a smaller box elder rooted a few yards away. We kids used to climb one tree and switch to the other.

Growing in the deep shade of its neighbor the box elder grew poorly until it was cut down by the property owner. But that plane tree has continued to thrive as I confirm when I drive past that property at least once a year.

Many years later as a biology major at SIU, Carbondale, I took Robert Mohlenbrock’s course entitled "Trees, Ferns, and Wildflowers," and I was hooked. I learned the binomial name of some two dozen forest trees, and the sycamore was one of them.

For years I could run through the binomial names of all those species in my mind and that helped germinate my career. The American sycamore is ensconced in my psyche and enshrined in my botanical soul. It is something like my personal totem in the deep woods of home.

And that strange, singular tree on the hillside has become a beacon pointing the way for me to do forever what I last hope to do on Earth.