Prairie Bush-clover

Lespedeza leptostachya

Description

Prairie bush-clover, Lespedeza leptostachya, is an herbaceous perennial. Simple or slightly branched stems grow from a woody rhizome to a height of about 39 in (1 m). It has three-part (trifoliate) compound leaves with linear leaflets, covered with silvery-white hairs. The plant develops a slender flowering spike that produces 15 to 30 flowers from late July through mid-September. Flowers are of two types and both can occur on the same plant. Open (chasmogamous) flowers have petals that are white to yellowish white and a corolla that is pink to light purple. Closed (cleistogamous) flowers have cream-colored petals that are self-pollinating.

Habitat

Prairie bush-clover, a colonizer of open habitats, inhabits gravelly and well-drained dry prairies. It particularly prefers the slopes of kames and eskers, hills composed of glacially deposited material. Prairie bush-clover can be crowded out by perennial grasses or shaded out by woody species. It proliferates after a wildfire removes plant competitors. Prairie bush-clover is often found in association with a near relative, L. capitata.

Distribution

This clover is restricted to Midwestern prairies and is one of about 40 species of Lespedeza worldwide, of which 12 are found in North America. It has always been found in limited numbers in localized sites throughout its four-state range. Historically, it was found in eight Illinois counties, 22 counties in northern and south-central Iowa, and in portions of western Wisconsin and southern Minnesota.

Populations throughout the range have been separated into two categories: core and peripheral. Core populations typically consist of at least several thousand plants, while peripheral ones usually number only in the hundreds. The species is most numerous in Minnesota and Iowa, less so in Illinois and Wisconsin.

In Iowa, as of 1987, 13 populations were known from nine counties. Four Dickinson county sites comprised a core grouping of more than 5,000 plants, while other smaller sites, totaling no more than 1,000 plants were found in Butler, Clarke, Emmet, Howard, Kossuth, Osceola, Story, and Winneshieck Counties. The two largest Dickinson County sites—at Cayler Prairie and Freda Hafner Prairie—are owned by the state and by the Nature Conservancy.

In Minnesota, prairie bush-clover was known in 1987 from 11 sites in five southern counties: Brown, Cottonwood, Jackson, Goodhue, and Renville. The largest populations occured in Jackson County in numbers approaching 16,000 individual plants. Two core sites owned by the Nature Conservancy and by the state—at Red Rock/Delton Prairies and at Kilen Woods State Park—comprised the majority of plants.

In Wisconsin, there were four extant peripheral populations in four southern counties—Dane, Pierce, Rock, and Sauk. In 1987 the largest population, at Schluckebier Prairie in Sauk County, consisted of about 650 plants. Combined numbers from the other sites were less than 250. By 1981, prairie bush clover had declined at the four known Illinois sites to about 66 individual plants. A subsequent 1987 survey noted seven sall sites in five northern counties—Cook, DuPage, Lee, Ogle, and McHenry—with a total of less than 800 plants.

Threats

Prairie bush-clover occurs in a small fraction of its original range, which once encompassed hundreds of thousands of acres of native prairie. Most prairie has been converted to large-scale agricultural uses.

Conservation and Recovery

Most Iowa populations are within state or county preserves. One site in Illinois is owned by the state transportation department. One Minnesota site is owned by the Minnesota Historical Society, another by a private college. The state of Minnesota has initiated a long-term research project for managing this plant and has encouraged commercial production of seeds.

Voluntary participation, rigorous respect of landowners' rights, and a personalized educational approach are three important features of Wisconsin's successful landowner contact program, which has helped numerous species, including the prairie bush-clover. Initiated in 1991, the state's effort seeks to protect endangered plants and animals that occur on private lands. This goal is carried out under a signed memorandum of understanding (MOU) between the landowner and the Wisconsin Bureau of Endangered Resources. Such an MOU has been helpful in protecting a prairie bush-clover population on land owned by a church in River Falls, Wisconsin, where an isolated cemetery prairie provides a home to this threatened plant species. Parishioners and priest alike have joined forces, signing an MOU and pledging themselves to the conservation goal.

All four states offer the species some degree of protection under state laws. Monitoring and legal enforcement, however, are often hampered by a shortage of personnel. The Nature Conservancy has purchased sites in all four states and has negotiated with private landowners to protect other populations.

Contact

U. S. Fish and Wildlife Service
Regional Office, Division of Endangered Species
1 Federal Drive
BHW Federal Building
Fort Snelling, Minnesota 55111
Telephone: (612) 713-5360
http://midwest.fws.gov/

References

Sather, N. P. 1988. "Studies of Lespedeza leptostachya at Red Rock Prairie, Minnesota." Report. Nature Conservancy Minnesota Field Office, Madison.

U. S. Fish and Wildlife Service. 1988. "Prairie Bush-Clover Recovery Plan." U. S. Fish and Wildlife Service, Twin Cities, Minn..