Appearance

Nymphoides cristata is an herbaceous aquatic plant with floating stems from a buried rootstock. Slender tuberous roots dangle from the stem-leaf node.

Foliage

Nymphoides cristata has a single heart-shaped leaf with smooth margins, cordate base, and short petiole at the tip of each stem.

Flowers

Flowers of Nymphoides cristata are white, with membranous margins, 0.3-0.9 in. (0.8-2.3 cm) wide, petal lobes with a ruffled crest (like a rooster’s comb) along the upper midvein, blooming from summer to fall.

Fruit

The fruit is an oblong capsule, with smooth, rounded seeds.

Ecological Threat

Nymphoides cristata was first introduced to the U.S. as a water garden plant. Fragments of the plant are spread by wind, flowing water, boats, and trailers. Infestations of Nymphoides cristata were first observed in cypress swamps and water management canals in southeast Florida in the late 1990s. Within a few years, large canals and suburban lakes in the central and eastern parts of the state had become infested. There is serious concern about this plant because herbicides that control other floating and emergent invasive plants have had little effect on it. Similar natives are Big Floating Heart (N. aquatica), Little Floating Heart (N. cordata), and Water Snowflake (N. indica). Nymphoides cristata is still being sold in the water garden trade.

Resources

• EDRR Fact Sheet - Invasive Plant Control, Inc.
• Images and Information - University of Florida - Center for Aquatic and Invasive Plants

Selected Images

Maps

Invasive Listing Sources

• Florida Invasive Plant Council - Plant List - Category I
• Florida Noxious Weeds
• North Carolina Noxious Weeds
• South Carolina Invasive Pest Council
• South Carolina Plant Pest List

References