After light rain in the morning, it cleared by noon, so this tour of the Grady tract took place mostly under sunny skies, but with occasional clouds. Several participants commented upon how comfortable the around 70-degree temperature felt compared to more than 85 degrees with high humidity of the past few days.
Using the educational sign just inside the Grady tract entrance gate, I pointed out where Greene Prairie was and briefly mentioned a few of the other major plant communities we would see. The first was the Evjue Forest, a red pine plantation, planted during the 1940s. Someone asked what the current management plan is for the row-planted pine forest and what, if anything, would be done with the dead pines. I decided this was a good question for the Arboretum ecologist.
We stopped to admire the pokeweed that has taken over the area where a previous research experiment cleared the forest floor to study the rate of invasive plants filling in the cleared space. I doubt they anticipated all that pokeweed would be the dominant species in their study plots.
The glacier kettle hole is very visible now that the underbrush has been mostly cleared away. Most of the group had heard of how glaciers create kettles when they deposit huge blocks of ice that melt slowly and leave large depressions. We also looked at the huge burl on the tree by the kettle.
Approaching the West Grady Knoll, we noticed several common goldenrods, Solidago canadensis. Careful observation of the leaves, flower clusters, and height allowed us to identify it. The goldenrods are in full bloom on the West Grady Knoll. The dominant species, both in height and frequency, is Canada goldenrod. Showy goldenrod, Solidago speciosa, are numerous and easily identified by their bright yellow vertical inflorescences. Also common are the stiff goldenrod, Solidago rigida, with their stiff stems, somewhat egg-shaped stiff clasping leaves, and their flat-top cluster of yellow flowers. Later we found a few dyer’s-weed goldenrods, Solidago nemoralis, with their flowers on the top of short, backward-curving branchlets, and Riddell’s goldenrod, solidago riddellii, with more grasslike leaves and flat-topped to slightly round-topped inflorescence. This certainly is the time of year when the bright yellow goldenrods dominate the Arboretum grasslands.
While walking across the West Grady Knoll we started noticing a variety of asters in bloom. I am unsure of my identification of some of the similar asters. For example, I know there are smooth asters, Symphyotrichum laeve, silky aster, Symphyotrichum sericeum, and sky-blue aster, Symphyotrichum oolentangiense. To me they are very similar beautiful purplish asters. We enjoyed how the bright purplish asters complement the bright yellow goldenrods.
On the knoll we noticed the bright red of sumac leaves and the beginning of the oak leaves turning tan. Even though we have just had some of the warmest days of this summer, with temperatures in the upper 80s, it is evident that fall is approaching.
Arriving at the edge of Greene Prairie, we reviewed the history of how Professor Henry Greene came to create this magnificent prairie, mostly by himself, from 1943 to 1964. To plant more than 12,000 plants on this 40 acres during the first few years, he must have devoted most of his waking hours to creating this prairie. As this story of his efforts is related in Arboretum history, he insisted on doing all this work mostly by himself. It was not until late in the 1950s that he agreed to allow Professor Jim Zimmerman to help him. The result is what is often referred to as the most successful creation of an authentic Midwestern prairie to date.
As we started out onto Greene Prairie we couldn’t help but notice the beautiful bright purple bottle gentians, Gentiana andrewsii. At first we saw a few, some with numerous flowers in larger clusters, and shortly we realized that this is a bumper year for the bottle gentians. I have never seen so many flowering at the same time, and we only saw the ones in flower near the trail. Along with the bottle gentians we found fringed gentians, Gentianopsis crinita, with delicate fringes on the outer edge of each flower petal. Both these gentians seem particularly vibrant this year.
A short distance along the trail we discovered our first stiff gentians, Gentianella quinquefolia. We had found three of the five gentians known to be in Greene Prairie. I hoped to find a few downy gentians, Gentiana puberulenta and maybe a cream gentian, Gentiana alba, but the first three gentian species were all we found. They sure add a vibrant purple to the greens, yellows, and other colors of this prairie.
Further along we came upon a lot of leaves of compass-plant, Silphium laciniatum, and prairie-dock, Silphium terebinthinaceum, but no flowering stalks. Past years these two silphiums have dominated parts of Greene Prairie with their tall sunflower covered stalks. This year, for some unexplained reasons, very few are in bloom. I wonder what the reasons are.
We did manage to find a few lady’s-tresses, Spiranthes magnicamporum, along the trail. They are very delicate and add a nice white touch to the prairie.
As you stand on the boardwalk trail and gaze across Greene Prairie, you can’t help but notice the large areas covered by native sunflowers. The prevalent one is saw-tooth sunflower, Helianthus grosseserratus. The flowers rise above most of the prairie grasses and have larger yellow flowers than most other sunflowers. We did not distinguish many of the numerous sunflower species, choosing instead to just enjoy their yellow flowers and notice the patches where they dominated the prairie vegetation.
Walking back to the start of our tour, we spoke about what a delightful day to experience the Grady tract, and particularly the grasslands, that are full of colorful flowers now.