– Canadian waterweed, common waterweed, Rocky Mountain waterweed
Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska to California, east across most of North America to the Atlantic Coast.
Habitat: Common in ponds, lakes, streams, rivers, and slow-moving waters.
Origin: Native
Flowers: July-September
Growth Duration: Perennial
– Nuttall's waterweed, western waterweed
Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia to California and Nevada, east to the Great Plains, midwestern U.S., and northeastern North America.
Habitat: Fresh to slightly brackish water of streams, rivers, lakes, ponds, and backwaters at low to middle elevations.
Origin: Native
Flowers: July-September
Growth Duration: Perennial