Distribution: Occurring west of the Cascades crest in Washington, where known only from Thurston County; southern British Columbia to Oregon, also in eastern North America.
Habitat: Lakes, sloughs, ditches, slow streams.
Flowers: June-August
Origin: Native
Growth Duration: Perennial
Conservation Status: Not of concern
Pollination: Wind
[none provided]
PNW Herbaria: Specimen records of Myriophyllum pinnatum in the Consortium of Pacific Northwest Herbaria database
WA Flora Checklist: Myriophyllum pinnatum checklist entry
OregonFlora: Myriophyllum pinnatum information
E-Flora BC: Myriophyllum pinnatum atlas page
CalPhotos: Myriophyllum pinnatum photos