Yellow floating heart leaf and flower

Yellow floating heart (Nymphoides peltata)

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.

Overview

Regulated areas of yellow floating heart
Yellow floating heart is Prohibited (Red counties)

Other names for this plant include:

  • Common names: floating heart, fringed water lily, entire marshwort
  • Scientific names: N. natans; N. nymphaeoides; Limnanthemum petlatum

Ecological threat:

  • Invades lakes, riparian zones, water courses, wetlands.
  • Grows in dense patches, excluding native species and even creating stagnant areas with low oxygen levels underneath the floating mats.
  • Makes recreational activities like fishing, water skiing, swimming, and canoeing difficult, if not impossible.

Classification in Wisconsin: Prohibited

Species Assessment Groups (SAG) were assembled to recommend a legal classification for each species considered for NR 40. The recommendation for yellow floating heart was based upon this literature review developed by the department.

Identification

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; 5 petals 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 few to many smooth, shiny seeds with wing-like margins.

Roots: Short, thick clusters of roots originate from modified stems (rhizomes) growing partly or completely below the sediment.

Similar species: Spatterdocks (Nuphar spp.), which have much larger leaves, and cup-like flowers without fringed petals. Water shield (Brasenia schreberi) which 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), which are be sold as ornamental plants.

Distribution

See the reported locations of yellow floating heart.

Do you know of additional yellow floating heart populations? Send us a report.

Control

Mechanical: Harvesting can reduce the population, but frequent monitoring and follow up is required.

Chemical: Aquatic approved herbicides can be very successful. Application must be applied by a licensed applicator and may require a permit.

Photos

View yellow floating heart pictures in our photo gallery!

Resources

Sources for content:

  • Washington State Department of Ecology: Nyphoides peltata [exit DNR]
  • Global Invasive Species Database: Nymphoides peltata [exit DNR]. Last updated September 20, 2006.
  • Massechusetts Department of Conservation and Recreation Office of Water Resources, Lakes and Ponds Program. "Yellow Floating Heart: An Exotic Aquatic Plant", December 2004

Links for More Information

Last revised: Friday December 06 2013