United States, Wisconsin, Polk, North Pipe Lake and Pipe Lake
T35N R15W sec10
Rocky and sandy bottoms in 0 meter of water. Common assoc.: (Eleocharis palustris) creeping spikerush, (Schoenoplectus acutus) hardstem bulrush, (Eleocharis obtusa) blunt spikerush.
Relatively common in scattered reed beds at the shoreline on both north lake and main lake; especially exposed points. [There is a duplicate accession number for a specimen of Spirodela polyrrhiza - editor added "a"]