Lycopus americanus Muhl.
Common Name: COMMON WATER HOREHOUND
Coefficient of Conservatism: 2
Coefficient of Wetness: -5
Wetness Index: OBL
Physiognomy: Nt P-Forb

Very common throughout Michigan, nearly always in moist to wet places: shores, edges of marshes and ponds, fens and springy areas, ditches and swales, river and stream margins, swamps, wet gravel pits and other excavations (or filled ground).

Variable in leaf form, pubescence, and other characters. The stems are ± densely hairy at the nodes that lack flowers, but the internodes vary from glabrous to hairy. The upper surface of the leaves is usually glabrous, often scabrous, but may have a few hairs especially toward the base, a feature normally associated with L. europaeus. Both species have a very sharply 4-angled stem and nutlets usually 1.2–1.7 mm long. Both lack surficial runners, though they are rhizomatous, while all our other species except L. asper frequently produce slender elongate runners.

Locations

Alcona County
Alger County
Allegan County
Alpena County
Antrim County
Arenac County
    Including Charity Island
Baraga County
Barry County
Bay County
Benzie County
Berrien County
Branch County
Calhoun County
Cass County
Charlevoix County
    Including Beaver Island
Cheboygan County
Chippewa County
    Including Drummond Island
Clare County
Clinton County
Crawford County
Delta County
Dickinson County
Emmet County
Genesee County
Grand Traverse County
Gratiot County
Hillsdale County
Houghton County
Huron County
Ingham County
Ionia County
Iosco County
Iron County
Isabella County
Jackson County
Kalamazoo County
Kalkaska County
Kent County
Keweenaw County
    Including Isle Royale
Lake County
Lapeer County
Leelanau County
    Including Fox Islands
    Including Manitou Islands
Lenawee County
Livingston County
Luce County
Mackinac County
    Including Bois Blanc, Mackinac, Round Islands
Macomb County
Manistee County
Marquette County
Mason County
Mecosta County
Menominee County
Midland County
Missaukee County
Monroe County
Montcalm County
Montmorency County
Muskegon County
Newaygo County
Oakland County
Oceana County
Ogemaw County
Ontonagon County
Oscoda County
Ottawa County
Presque Isle County
Roscommon County
Saginaw County
Sanilac County
Schoolcraft County
Shiawassee County
St. Clair County
St. Joseph County
Tuscola County
Van Buren County
Washtenaw County
Wayne County
Wexford County

Citation:

MICHIGAN FLORA ONLINE. A. A. Reznicek, E. G. Voss, & B. S. Walters. February 2011. University of Michigan. Web. December 17, 2017. http://michiganflora.net/species.aspx?id=1557.