Plant Science & Conservation
The Dune Willow
Collecting seed from a dune willow. Photo by Grant Fessler.
A January 2020 storm had battered the park’s dunes and pushed Lake Michigan inland, flooding vast areas of the park. Now Johannesen, a volunteer for the Chicago Botanic Garden’s Plants of Concern rare plant monitoring program, aimed his camera at the fallout—dune willows almost fully submerged, others tethered to sand by just a few roots.
Dune willow at Illinois Beach State Park submerged after a late winter storm. Photo by David Johannesen.
Because so little of Lake Michigan’s shoreline remains undisturbed, dune willow survives at just a few sites in Illinois and is listed as endangered in the state.
Dune willow’s spring blooms provide meals for early emerging pollinators and its leaves feed the caterpillars of many butterflies and moths. When healthy, the plants play an important role in Illinois Beach’s dune and swale landscape—dry sandy ridges alternating with wet depressions—which features a mosaic of uncommon prairies, savannas, and globally rare wetlands.
Illinois Beach supports more than 500 plant and 300 animal species, and each time a species disappears it leaves a hole that tears at the fabric of the entire site, making it more vulnerable to impacts from human development and climate change.
Plants of Concern would not just watch as dune willow disappeared.
Left: Cuttings taken from surviving dune willows at Illinois Beach State Park. Right: Dune willows grown from the cuttings at the Garden. Photos by Gretel Kiefer.
Working with a sense of urgency, a team from Plants of Concern and the Illinois Department of Natural Resources, took cuttings from the surviving dune willows that spring. By June, they had nearly 60 new plants—grown by the Garden’s plant production staff—ready to go back to Illinois Beach.
But plants grown from cuttings are clones, genetically identical to the plant they are cut from. To build a more resilient, genetically diverse population, they would need the dune willows to produce seed. With 12 surviving dune willows and individual plants having only male or female flowers, the team needed to get creative to help them reproduce.
Planting around the surviving dune willows, they established groups of genetically mixed male and female plants—some in wetter areas, some in drier, hoping to ensure a portion survived the unforgiving conditions along the lakefront. And, as Plants of Concern does, they collected a lot of data.
Volunteers planting dune willows at Illinois Beach State Park.
Walking over undulating dunes with a GPS unit, Plants of Concern staff and volunteers found seed on a female dune willow for the first time in June 2023—a little more than three years after they planted the first dune willow cuttings.
In October, Plants of Concern staff planted the first dune willows grown from seed, a major step toward securing a future for the species at Illinois Beach.