Myriophyllum heterophyllum Michx.
Coefficient of Conservatism: 6
Coefficient of Wetness: -5
Wetness Index: OBL
Physiognomy: Nt P-Forb

Myriophyllum heterophyllum P. M. Catling

Lakes and rivers, in water up to 4.6 m deep, though mostly shallower.

There is a rather frequent tendency for some of the leaves to be alternate in this species, so that vegetative fragments may resemble M. farwellii. This is a variable species in other respects as well. Stranded plants on moist shores may produce deeply serrate (or shallowly pectinate) “terrestrial” leaves or bracts; the tips of these or other aerial shoots if they become inundated may again produce typical dissected leaves.

The very short internodes and often more than 4 leaves at a node give this plant a very dense appearance; the long shoots look like green ropes under the water.


Alger County
Alpena County
Antrim County
Arenac County
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
Clinton County
Delta County
Emmet County
Genesee County
Gogebic County
Grand Traverse County
Gratiot County
Hillsdale County
Houghton County
Huron County
Iosco County
Jackson County
Kalamazoo County
Kent County
Keweenaw County
    Including Isle Royale
Leelanau County
    Including Fox Islands
Lenawee County
Livingston County
Mackinac County
Macomb County
Marquette County
Menominee County
Midland County
Monroe County
Montmorency County
Muskegon County
Oakland County
Ontonagon County
Presque Isle County
Schoolcraft County
St. Clair County
St. Joseph County
Washtenaw County


MICHIGAN FLORA ONLINE. A. A. Reznicek, E. G. Voss, & B. S. Walters. February 2011. University of Michigan. Web. June 29, 2022.