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General Information About
Yellow Floating Heart
(Nymphoides peltata)
Yellow floating heart is a perennial, waterlily-like
plant that carpets the water surface with long-stalked
heart-shaped leaves. The showy five-petaled yellow flowers occur
on long stalks and rise a few inches above the water. Yellow
floating heart is a native of Eurasia and the Mediterranean area
and has been introduced into Washington, particularly along the
Spokane River near Spokane.
Because of the attractive yellow flowers, this
plant has been sold as an ornamental water garden plants. It was
recently prohibited for sale in Washington by the Washington
Department of Agriculture and was listed as a Class B noxious weed
in 2001. For obvious reasons, lake residents are strongly
discouraged from planting yellow floating heart in lakes or
natural waterbodies. These plants appear to be aggressive growers
and sometimes "hitchhiker" plants such as hydrilla can also be
introduced to our lakes when nursery or mail order species are
planted.
Growth Habit
Like other floating leaved plants, yellow
floating heart grows in dense patches, excluding native species
and even creating stagnant areas with low oxygen levels underneath
the floating mats. These mats make it difficult to fish, water
ski, swim, or even paddle a canoe through. It prefers to grow in
slow moving rivers, lakes, reservoirs, and ponds.
Floating water heart reproduces by water
dispersed seeds and by new stolens. Broken off leaves with part of
a stem will also form new plants.
Management
We have had no direct experience controlling
yellow floating heart in Washington. However yellow floating heart
has a similar growth habit to the fragrant waterlily and it is
expected that methods used to manage waterlilies would also be
effective on yellow floating heart. Waterlilies (and yellow
floating heart) can be controlled by cutting, harvesting, covering
with bottom barrier materials, and aquatic herbicides
(Rodeo®). Grass carp do not eat waterlilies in Washington and it
is not known if they would readily eat yellow floating heart.
Identification
Look for the following characteristics:
- Bright, yellow flowers about an inch or so in
diameter.
- Two to five flowers from each flower stalk.
- Five petals per flower with a distinctive
fringe along the edges of the petals.
- Petals arranged like the spokes of a wheel.
- Heart-shaped floating leaves with slightly
wavy margins and purplish undersides.
Don't confuse yellow floating heart with
Spatterdock (also called yellow pond or cow lily) which has a
yellow "ball-shaped" flower and large elephant-ear-shaped leaves.
Another look-alike plant, watershield, has small floating leaves
with the underside often coated in a gelatinous slime. Watershield
has inconspicuous purple flowers. There are also other ornamental
species of Nymphoides sp. that are sometimes sold at
aquatic plant nurseries and may be confused with yellow floating
heart.
Source: Washington State
Department of Ecology |
