Carex crus-corvi Shuttlw. ex Kunze
Raven's Foot Sedge
Basis for Former Listing
Carex crus-corvi is distributed along drainages of the Mississippi River and also along the southeast coastal plain (Standley 2002). Range-wide it is found in wetland habitats and along floodplains. Carex crus-corvi tends to be rare on the edges of its range (to the north, west, and east) and is considered critically imperiled in Wisconsin, Nebraska, Ontario, Virginia, and North Carolina (NatureServe 2011). Minnesota represents the northwestern-most limit of the species' range (Wheeler 1981).
Basis for Delisting
When C. crus-corvi was designated a special concern species, some potential habitat still remained to be surveyed. Despite botanical inventory work in Goodhue and Wabasha counties and some efforts to specifically search for this species, no remnant populations of C. crus-corvi have been discovered. The loss of this species in Minnesota may be the result of the drastic alteration of its habitat caused by the extensive lock and dam system constructed on the Mississippi River in the 1930s. Carex crus-corvi is now considered extirpated from Minnesota. Therefore, special concern status is no longer necessary and the species was delisted in 2013.
References and Additional Information
Minnesota Department of Natural Resources. 2012. Statement of need and reasonableness. Minnesota Department of Natural Resources. Division of Ecological and Water Resources. St. Paul, Minnesota. 337 pp.
NatureServe. 2011. NatureServe Explorer: An online encyclopedia of life [web application]. Version 7.1. NatureServe, Arlington, Virginia.
Rosendahl, C. O., and J. W. Moore. 1947. A new variety of Sedum rosea from southeastern Minnesota and additional notes on the flora of the region. Rhodora 49:197-202.
Standley, L. A. 2002. Carex sect. Vulpinae. Pages 273-278 in Flora of North America Editorial Committee, editors. Flora of North America north of Mexico. Volume 23. Oxford University Press, New York, New York.
Wheeler, G. A. 1981. A study of the genus Carex in Minnesota. Dissertation, University of Minnesota, St. Paul, Minnesota. 501 pp.
Wisconsin Department of Natural Resources. 1992. Endangered resources handbook 1724.5. Wisconsin Department of Natural Resources, Madison, Wisconsin. 283 pp.
Wisconsin Department of Natural Resources [WIDNR]. 2010. Ravenfoot Sedge (Carex crus-corvi).
Yatskievych, G. 1999. Steyermark's flora of Missouri. Second edition, Volume 1. Missouri Department of Conservation, Jefferson City and Missouri Botanical Garden Press, St. Louis, Missouri.