Identification: When flowers are present, this species of Nymphoides is easy to differentiate from other species of the genus. Flowers are white, with yellow throats, five-petaled, and have a distinct erect fold of petal tissue, or “crest,” along the midvein of the upper surface of each petal lobe (Burks 2002). Flowers 1-2 cm wide. Fruits are capsules (6 mm long) and contain up to 20 seeds. Flowers may be pistillate (female) or hermaphroditic (both male and female) (Tippery and Les 2011). Flowers clustered and borne at distal stem nodes that rise just above the water surface (Burks 2002; Anderson and Frank 2014).
Nymphoides cristata plants mostly are rooted in the bottom sediments of shallow waters, but can be free-floating with clusters of tapered tuberous roots suported by floating leaves (Willey and Langeland 2011).
Leaves ovate to circular and often reddish or purple below. Leaf margins are entire and often tinged red. Leaves form at the terminus of long floating stems. When subtending leaf tubers mature, the plant becomes free-floating for a period of time (Burks 2002).
† Populations may not be currently present.
Ecology: The genus Nymphoides contains approximately 50 species globally (Tippery and Les 2011), mostly found in tropical regions (Ornduff and Mosquin 1970).
Nymphoides cristata disperses vegetatively when leaves and associated adventitious roots become free-floating for a period of time, eventually sinking to the bottom and giving rise to new plants (Mason and van der Valk 1992; Willey and Langeland 2011).
The plant reproduces vegetatively from tubers, daughter plants, rhizomes and fragmentation. Once established, this species rapidly colonizes and spreads to new locations in the waterbody to form mats of overlapping floating leaves that shade submersed aquatic vegetation. Dense mats impede water flow and can reduce dissolved oxygen in the water column below the mat (Burks 2002; Willey and Langeland 2011).
References: (click for full references)
Anderson, L.C. (curator). 2009. Herbarium Specimen Voucher Data, Florida State University (FSU), Herbarium. Florida State University, Tallahassee, FL. http://herbarium.bio.fsu.edu/.
Anderson, P.J., and M.S. Frank. 2014. Pest alert: Nymphoides cristata, crested floating heart, a recently listed state noxious weed. Florida Department of Agriculture and Consumer Services, Division of Plant Industry, Avon Park, FL. http://www.freshfromflorida.com/content/download/40357/871941/Pest-Alert_Nymphoides-cristata.pdf.
Baker, R.J. 2015. Aerial treatments underway for invasive plants on lake. Manning Live. Manning, SC. http://manninglive.com/2015/07/30/aerial-treatments-underway-for-invasive-plants-on-lake/. Created on 07/29/2015. Accessed on 08/14/2015.
Burks, K.C. 2002. Nymphoides cristata (Roxb.) Kuntze, a recent adventive expanding as a pest plant in Florida. Castanea 67(2):206-211.
Center for Invasive Species and Ecosystem Health. 2015. EDDMapS: Early detection and distribution mapping system. The University of Georgia, Tifton, GA. http://www.eddmaps.org.
FLEPPC. 2015. List of Invasive Plant Species. Florida Exotic Pest Plant Council. http://www.fleppc.org/list/list.htm.
Mason, D., and A.G. van der Valk. 1992. Growth responses of Nymphoides indica seedlings and vegetative propagules along water depth gradient. Aquatic Botany 42:339-350.
Ornduff, R. 1966. The origin of dioecism from heterostyly in Nymphoides (Menyanthaceae). Evolution 20(3):309-314.
Ornduff, R., and T. Mosquin. 1970. Variation in the spectral qualities of flowers in the Nymphoides indica complex (Menyanthaceae) and its possible adaptive significance. Canadian Journal of Botany 48:603-605.
Texas Invasive Plant and Pest Council. 2015. Texas Invasives Database. http://www.texasinvasives.org/. Accessed on 11/20/2015.
Tippery, N.P., and D.H. Les. 2011. Phylogenetic relationships and morphological evolution in Nymphoides (Menyanthaceae). Systematic Botany 36(4):1101-1113.
University of Connecticut. 2011. CONN. University of Connecticut, Storrs, CT. http://www.gbif.org/dataset/5288946d-5fcf-4b53-8fd3-74f4cc6b53fc. Created on 09/08/2011. Accessed on 11/20/2015.
Willey, L.N., and K.A. Langeland. 2011. Aquatic weeds: crested floating heart (Nymphoides cristata). Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL.
This information is preliminary or provisional and is subject to revision. It is being provided to meet the need for timely best science. The information has not received final approval by the U.S. Geological Survey (USGS) and is provided on the condition that neither the USGS nor the U.S. Government shall be held liable for any damages resulting from the authorized or unauthorized use of the information.