Aquatic Plants - invasive

Floating Marsh-Pennywort (Hydrocotyle ranunculoides) on Sep 29, 2025

Description of specimen

Submitter has sample

Rapidly spreading mats of very dense floating pennywort.

Commentary

None

Remedy

This species is native to the Pacific Northwest, but some recently discovered populations have shown invasive characteristics. Research is ongoing, and locations from this site will be useful in determining the status of these populations.

Location

Floating marsh pennywort mats in Swan Lake, Cox Creek and Waverly Lake started this year.

Expert Reviewer

Avatar of Reviewer

Jacob Rose
Institute for Natural Resources

Maintained by Oregon State University | Contact us for questions regarding site content