Kentucky coffeetree. Photo: Christopher Reisetter
NLI’s Legacy Tree Program
(Measurements have been corrected since this story originally appeared to match the official Illinois Big Tree Register record.)
Confirmed in 2025 this is the Illinois State Champion Kentucky Coffeetree and officially part of the Illinois Big Tree Register.
Natural Land Institute is pleased to announce the September Tree of the Month is located in Dahlquist Park, Rockford, Ill. It is a Kentucky Coffeetree (Gymnocladus dioicus) that stands 87 feet tall, 52-feet average crown spread, with a circumference of 134.1 inches.
While checking on a tree nominated for Legacy Tree status in Rockford’s Dahlquist Park, NLI discovered a tree that will be another state champion! Executive Director, Alan Branhagen remarked “I saw the largest Kentucky Coffeetree I have ever seen.” NLI Trustee and volunteer, Howard Knodle, later measured the tree and confirmed its score does make it larger than the current state champion. (Paula Olson, Miracle Mile Executive Director, nominated a nearby, 80-foot tall European Larch).
The Kentucky coffeetree is on the right side of this photo. Photo: Christopher Reisetter
Dahlquist Park is a Rockford Park District property named after Ray Dahlquist. Mr. Dahlquist died in 1970 while a Park commissioner (1949-1970) and the current park was named in his honor upon his death. Seth B. Atwood, another Park District commissioner around that time as well as local industrialist and philanthropist, promoted planting Kentucky Coffeetrees. According to Bruce Atwood, Seth’s grandson, he thought they were under-appreciated and that there were too few of them. This coffeetree and its neighbors were likely planted because of the encouragement of Seth Atwood.
Kentucky Coffeetree is a native tree to Winnebago County found sparingly along the Rock, Pecatonica and Kishwaukee Rivers. It has a unique biology that ties it to extinct megafauna.
An “ecological anachronism” where species like giant ground sloths and mastadons that dispersed the seeds are extinct. Indigenous peoples played a game with its large, hard-coated seeds and probably saved the tree from extinction. “The tree got its name allegedly from settlers in Kentucky using its ground seeds as a coffee substitute but don’t try that because they have been determined to be toxic if ingested,” remarked Branhagen. “The seedcoat is so hard you need a hack saw to cut into it!”
Kentucky Coffeetrees usually produces either male or female flowers – female flowering trees form the short, thick pods that contain the nickel-sized seeds. Male flowers make pollen and both have a unique scent reminiscent of a lemony floor wax to entice pollinators. Occasionally trees can produce flowers of both sexes (polygamodioecious!). Male trees have been cloned for planting where no potentially messy pods are produced.
The tree has the largest leaf of any locally native plant but is comprised of leaflets in a herringbone pattern along leaf stems (rachises) – doubly pinnate is the botanical term. The leaf stems drop along with the leaflets in the fall leaving a thick coarse twig behind – and why small trees look silly. They are the ugly duckling that matures to a swan.
The wood from this tree is beautiful and valuable but the tree is too rare to be of any commercial importance. As a garden tree, it is ideal as it has deep and coarse roots with a canopy of leaves that lets light through – both allowing one to readily grow shade loving plants, including turf, beneath the tree. The tree does not have a high wildlife value like oaks, hickories, and cherries – it actually offers little to local wildlife but does add to the overall variety of life around us.
Visit this tree in Dahlquist Park, part of Rockford’s Miracle Mile on East State Street. There are three other Legacy Trees in this park including a European Larch, massive American Elm and Paper Birch.
Close up of the Kentucky coffeetree in Dahlquist Park. Photo: Alan Branhagen
Background and For More Information:
Natural Land Institute launched the Legacy Tree Program in January of this year. It includes recognition of one tree a month that may be the largest of its kind, or have historical or cultural significance. Anyone may nominate a tree on private or public land from NLI’s 12 county region. Other components of the program, a list of the 12 counties, the online nomination form, and the tree of the month since January can be found at: https://www.naturalland.org/nlis-legacy-tree-program-january/, call 815/964-6666 or email info@naturalland.org.