WILMINGTON, Ill. (July 11, 2019) – Isoetes butleri (limestone quillwort) is an Illinois State endangered plant that the USDA Forest Service – Midewin National Tallgrass Prairie and the Chicago Botanic Gardens’ Plants of Concern program are partnering to monitor. Monitors are volunteers and staff. On a recent monitoring day several sprouts of the elusive limestone quillwort plant were being counted and measured because it resides in one of the rarest prairie community types in the world: the dolomite prairie.

Creating habitat for native Illinois prairie plants is essential to the mission of the USDA Forest Service – Midewin National Tallgrass Prairie. Midewin was established by the Illinois Land Conservation Act in 1996 for four purposes, including protecting 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, which is home to specialized plants evolved to utilize poor soils.

Dolomite prairies usually have very 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.

Some of the rare native plant species of dolomite are leafy prairie clover (dalia foliosa), limestine hedge-hyssop (gratiola quartermainiae), prickly pear cactus (opuntia humifusa) and more. Yes – cactus, which grows even in Illinois because of the splendid habitat of the dolomite prairie.

Rare birds like the king rail, yellow rail, black-necked stilt and others are sometimes seen on dolomite prairie. Even rare insects, like the red-veined leaf hopper, are able to thrive more vibrantly on the dolomite prairie.

“The dolomite prairie is always interesting,” said volunteer Gail Pyndus. Pyndus has been involved in the Plants of Concern project as a volunteer since 2003.

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.

Volunteers with the program currently help monitor over eight plant of concern species. The continued monitoring is being done to determine how the habitat might be for the reintroduction of buffalo clover (trifolium reflexum).