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USDA Symbol: NYPE
ODA rating: A
Yellow floating heart risk assessment
Noxious weed listing process
Oregon yellow floating heart distribution
Other common names
Asaza, entire marshwort, floating heart, and fringed water lily.
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||Images courtesy of Glenn Miller, Oregon Dept. of Agriculture
If images are downloaded and used from the ODA web site please be sure to credit the photographer.
Aquatic perennial. Grows rooted to the bottom in water depths of 2-13 feet. Floating leaves heart-shaped to circular, 1 to 4 in long, purplish underneath with slightly wavy margins. Leaves attached to long stalks that arise from creeping underwater rhizomes. Flowers bright yellow, 5-petaled, and 1 to 1 1/4 inch in diameter. Reproduces by seed and by rooting at nodes and will regenerated from plant fragments.
Yellow floating heart grows in dense patches, excluding light for native species and creating stagnant areas with low oxygen levels underneath the floating mats. These mats make it difficult to fish, water ski, swim or paddle. It displaces native plants and animals and decrease biological diversity. This troublesome aquatic changes how natural ecosystems work. Grows on slow-moving rivers, lakes, reservoirs, and ponds.
Introduced to the U.S. as an ornamental water plant from the Mediterranean area.
Distribution in Oregon
Two known sites in Oregon, one in Washington County found in 2004 and another in Lane County in 2005. Both sites had grown considerably in the past few years.
Biological control agents are not used on "A" listed weeds in Oregon. This weed is being managed for eradication.
Yellow floating heart printable trifold(pdf)