Distribution: Occurring west of the Cascades crest in western Washington; Alaska to northwest Washington, east to the Canadian Great Plains, Great Lakes region.
Habitat: Tidal flats, lakes, peatlands, and ditches.
Flowers: June-September
Origin: Native
Conservation Status: Sensitive in Washington (WANHP)
[none provided]
PNW Herbaria: Specimen records of Eleocharis mamillata ssp. mamillata in the Consortium of Pacific Northwest Herbaria database
WA Flora Checklist: Eleocharis mamillata ssp. mamillata checklist entry
OregonFlora: Eleocharis mamillata ssp. mamillata information
E-Flora BC: Eleocharis mamillata ssp. mamillata atlas page
CalPhotos: Eleocharis mamillata ssp. mamillata photos