Spirodela polyrhiza (L.) Schleid.
Common Name: GREATER DUCKWEED
Coefficient of Conservatism: 6
Coefficient of Wetness: -5
Wetness Index: OBL
Physiognomy: Nt P-Forb

Spirodela polyrhiza with Wolffia B. S. Walters with Wolffia

Floating on the surface of quiet water in ponds, lakes, ditches, marshes, backwaters and borders of rivers and streams, etc., often with Lemna and less commonly with Wolffia spp.

Locations

Alcona County
Alger County
Allegan County
Baraga County
Barry County
Bay County
Benzie County
Berrien County
Branch County
Calhoun County
Cass County
Charlevoix County
Cheboygan County
Chippewa County
Clare County
Clinton County
Crawford County
Delta County
Dickinson County
Emmet County
Gogebic County
Gratiot County
Hillsdale County
Houghton County
Ingham County
Iosco County
Iron County
Isabella County
Jackson County
Kalamazoo County
Kent County
Leelanau County
Lenawee County
Livingston County
Luce County
Manistee County
Marquette County
Mason County
Mecosta County
Midland County
Missaukee County
Monroe County
Muskegon County
Oakland County
Ogemaw County
Ontonagon County
Oscoda County
Ottawa County
Presque Isle County
Roscommon County
Shiawassee County
St. Clair 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 12, 2017. http://www.michiganflora.net/species.aspx?id=179.