Yellow floating heart
Perennial, water-lily-like plant with long-stalked, heart-shaped leaves. It is sometimes used as a water garden plant and can threaten waterbodies if spread to natural areas.
Other names for this plant include:
- Common names: floating heart, fringed water lily, entire marshwort
- Scientific names: N. natans; N. nymphaeoides; Limnanthemum petlatum
Classification in Wisconsin: Prohibited
- Ecological Threat
- Invades lakes, riparian zones, watercourses, and wetlands.
- Grows in dense patches, excluding native species and creating stagnant areas with low oxygen levels underneath the floating mats.
- It makes recreational activities like fishing, water skiing, swimming, and canoeing difficult, if not impossible.
Leaves: Heart-shaped and 3-10 cm across; alternately arranged on the stems and oppositely arranged on the flower stalks. Leaves float on the water surface, have slightly wavy margins and frequently have purplish undersides.
Flowers: 2-5 bright yellow flowers arise from erect flower stalks; 3-4 cm in diameter. Five petals are arranged like the spokes of a wheel, each with a distinctive fringe along the edges.
Fruits & seeds: Fruit is a long-beaked capsule (to 2.5 cm) that splits on one side. One fruit is produced from each flower and contains a few too many smooth, shiny seeds with wing-like margins.
Roots: Short, thick clusters of roots originate from modified stems (rhizomes) growing partly or entirely below the sediment.
Similar species: Spatterdocks (Nuphar spp.), which have much larger leaves and cup-like flowers without fringed petals. Water shield (Brasenia schreberi) has small oval floating leaves often with a jelly-like covering on the undersides, and small purple flowers. Also, other species of Nymphoides (N. aquatica and N. cordatum) are sold as ornamental plants.
See the reported locations of yellow floating hearts in Wisconsin.
Do you know of other populations? Please send us a report.
Mechanical: Harvesting can reduce the population, but frequent monitoring and follow-up are required.
Chemical: Aquatic-approved herbicides can be very successful. A licensed applicator must apply the application and may require a permit.
- Sources for content:
- Washington State Department of Ecology: Nyphoides peltata
- Global Invasive Species Database: Nymphoides peltata. Last updated September 20, 2006.
- Massachusetts Department of Conservation and Recreation Office of Water Resources, Lakes and Ponds Program. "Yellow Floating Heart: An Exotic Aquatic Plant," December 2004