Leonurus cardiaca L.
Common Name: MOTHERWORT
Coefficient of Conservatism: *
Coefficient of Wetness: 5
Wetness Index: UPL
Physiognomy: Ad P-Forb

Leonurus cardiaca A. A. Reznicek

A native of Europe and adjacent Asia, long cultivated and considered to have medicinal properties. In dry or swampy, often ± shaded disturbed ground: roadsides, railroads, dumps and refuse heaps, around buildings, farmyards, parking lots; dry open forests (e.g., oak), weedy floodplains, river banks, thickets, sandy banks and fields. Collected in Michigan as early as the First Survey (1837) in St. Joseph Co.

This is a tall, hard-stemmed plant, with the spiny calyx lobes spreading to reflexed at maturity. The nutlets are strongly 3-angled, flat and pubescent at the apex. The upper lip of the corolla is long-pilose, the buds thus appearing like hairy plugs in the calyx. A few specimens collected in the fall bear leaves (late-formed?) with rather rounded lobes and short sinuses, resembling those of a Ribes, rather than the usual shape with 3 long sharp-pointed lobes.

Locations

Alcona County
Allegan County
Alpena County
Antrim County
Arenac County
Barry County
Bay County
Benzie County
Berrien County
Branch County
Calhoun County
Cass County
Charlevoix County
    Including Beaver Island
Cheboygan County
Clinton County
Crawford County
Delta County
Eaton County
Emmet County
Genesee County
Gladwin County
Grand Traverse County
Gratiot County
Hillsdale County
Houghton County
Ingham County
Ionia County
Iosco County
Isabella County
Jackson County
Kalamazoo County
Kent County
Keweenaw County
Lake County
Lapeer County
Leelanau County
    Including Fox Islands
    Including Manitou Islands
Lenawee County
Livingston County
Macomb County
Manistee County
Marquette County
Mason County
Mecosta County
Menominee County
Missaukee County
Monroe County
Muskegon County
Newaygo County
Oakland County
Oceana County
Ontonagon County
Ottawa County
Presque Isle County
Roscommon County
Saginaw County
Shiawassee County
St. Clair County
St. Joseph County
Tuscola County
Van Buren County
Washtenaw County
Wayne County

Citation:

MICHIGAN FLORA ONLINE. A. A. Reznicek, E. G. Voss, & B. S. Walters. February 2011. University of Michigan. Web. December 16, 2017. http://michiganflora.net/species.aspx?id=1556.