Bacopa rotundifolia (Michx.) Wettst.

Washington: Benton County: Small cove, 0.6 air km N of Telegraph Island in Lake Umatilla, Umatilla National Wildlife Refuge, Ridge Unit. Elev. 80 m.
45.92067° N, 119.63089° W
Datum: WGS 84. Coordinate Source: Specimen Label.
Locally common in shallow water to 15 cm deep and on muddy shoreline, full sun or partial shade, over basalt, with Eleocharis obtusa, E. acicularis, Ludwigia palustris, Schoenoplectus acutus, Lythrum salicaria, Zannichellia palustris. Prostrate, white flowers.¶USAC Columbia River Plant Survey. Phenology: Flowers and Fruits.

Peter W. Dunwiddie PWD 18-502, Aug 15, 2018
With Peter F. Zika
WTU, Accession: 418888, Barcode: WTU-V-041970