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Natural Awakenings Chicago

Rare Habitat Hosts Unusual Species

Jul 24, 2019 04:21PM

Midewin Restoration Technician Grace Wu points to limestone quillwort (isoetes butleri) growing in dolomite prairie on the USDA Forest Service – Midewin National Tallgrass Prairie. Limestone quillwort is one of the rare plant species staff and volunteers with Midewin and the Chicago Botanic Garden are working in a partnership to protect. Photo by Veronica Hinke / USDA Forest Service Midewin NTP.

The U.S. Department of Agriculture ( Forest Service – Midewin National Tallgrass Prairie and the Chicago Botanic Garden ( are partnering in the Plants of Concern ( program to monitor Isoetes butleri (limestone quillwort), an Illinois endangered plant, and other types of Midwest “Plants of Concern.” Monitors comprise both volunteers and staff. The plant resides in one of the rarest prairie community types in the world: dolomite prairie. Creating habitat for native Illinois prairie plants is essential to the mission of the Midewin. Midewin was established by the Illinois Land Conservation Act in 1996 for four purposes, including providing habitat for native Illinois prairie plants.

        There are about 1,000 acres of dolomite prairie on the Midewin. At the core of dolomite prairie is magnesium-rich dolomitic limestone that is home to specialized plants evolved to take advantage of poor, shallow soils. In some places, bedrock is exposed in wide expanses. Prairie grasses and plants on dolomite prairie grow less densely and shorter than in other prairie ecoscapes. For instance, big bluestem reaches only about three-feet-tall, whereas in other parts of the Midewin, it can grow as high as six or seven feet. The hinderance of growth of more deep-rooting prairie plants allows for growth of some of the rarest of prairie species.

         Other rare native plant species of dolomite prairie are leafy prairie clover (Dalia foliosa), limestone hedge-hyssop (Gratiola quartermainiae), prickly pear cactus (Opuntia humifusa) and others. Rare birds like the king rail, yellow rail, black-necked stilt and others are sometimes seen on dolomite prairie. Rare insects, like the red-veined leaf hopper, are able to thrive.

         Volunteers monitor for the rare plants in hot conditions and sometimes in areas with mud and puddles. These conditions are best for monitoring because they coincide with the highest plant growth. “The dolomite prairie is always interesting,” says Gail Pyndus, who has been involved in the Plants of Concern project as a volunteer since 2003.


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