Distribution: Occurring west of the Cascades crest in Washington; southwestern Washington to California; also in the southeastern U.S., where native.
Habitat: Silty or gravelly riverbanks, and sandy depressions.
Flowers: June-August
Origin: Introduced from the southeastern U.S.
Growth Duration: Perennial
Conservation Status: Not of concern
[none provided]
PNW Herbaria: Specimen records of Juncus diffusissimus in the Consortium of Pacific Northwest Herbaria database
WA Flora Checklist: Juncus diffusissimus checklist entry
OregonFlora: Juncus diffusissimus information
E-Flora BC: Juncus diffusissimus atlas page
CalPhotos: Juncus diffusissimus photos