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The Nonindigenous Occurrences section of the NAS species profiles has a new structure. The section is now dynamically updated from the NAS database to ensure that it contains the most current and accurate information. Occurrences are summarized in Table 1, alphabetically by state, with years of earliest and most recent observations, and the tally and names of drainages where the species was observed. The table contains hyperlinks to collections tables of specimens based on the states, years, and drainages selected. References to specimens that were not obtained through sighting reports and personal communications are found through the hyperlink in the Table 1 caption or through the individual specimens linked in the collections tables.

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Common name: water spinach

Synonyms and Other Names: Ipomoea reptans

Taxonomy: available through www.itis.gov

Identification: A hollow-stemmed perennial vine with stems that reach lengths up to 4 meters and may float on the water surface, creep on mud or grow over other plants.  Leaves are variable, but typically are 3-15 cm long, and 1-10 cm wide, alternately arranged along the stem and sagittate (arrowhead-shaped).  Basal lobes rounded or acute and apex acute to obtuse and the leaf margin may appear slightly sinuate.  Petioles are long, ranging from 3-20 cm.  The showy morning-glory-like flowers are up to 5 cm wide, funnel-shaped and range in color from white to pink to pale lilac.  Plants may go dormant during dry months, with reduced stems and leaves (Holm et al. 1997).  Reproduction via seed and vegetative fragments (Holm et al. 1997, Wagner et al 2005). 

Native Range: Central and south China, India, Sri, Lanka, and Thailand.

Alaska	Hawaii	Puerto Rico & Virgin Islands	Guam Saipan

Hydrologic Unit Codes (HUCs) Explained
Interactive maps: Point Distribution Maps

Ecology: Grows in still to flowing aquatic fresh-water habitats including shallow waters of canals, pools, ditches, lakes, swampy lowlands, and rice fields.  Intolerance to frost limits its distribution to tropical to warm temperate areas.

Means of Introduction: Infestations may be intentional or accidental, resulting from seed or vegetative fragments escaping cultivation or contaminated agricultural crops like rice, jute, cocoa, peanuts (Holm et al. 1997).  

Status: Federal Noxious Weed List (as of June 30, 2006).   

Impact of Introduction:

Summary of species impacts derived from literature review. Click on an icon to find out more...

Ecological	Economic	Human Health

This weedy species infests up to 20 crops world-wide and many of its impacts are similar to other well known aquatic weeds like Eichhornia, Pistia and Salvinia.  Intertwined stems form dense mats on water surfaces, shading out native submersed aquatics and competing with emergent species which may be important for fish and wildlife (PIER 2008).  These masses of tangled vegetation can slow water flow in drainage and flood control canals (Holm et al. 1997). Stagnant water resulting from infestations of water spinach may become breeding grounds for mosquitoes and in its native range of Thailand I. aquatica is known to provide habitat for snails that are vectors for human diseases (Holm et al. 1997, ISSG 2006).  

References: (click for full references)

Global Invasive Species Database (GISD). 2006. Profile of Ipomoea aquatica (vine, climber). Invasive Species Specialist Group.  Online resource at: (accessed 12 February 2008).

Holm, L., J. Doll, E. Holm, J. Pancho, and J. Herberger. 1997. World Weeds: Natural Histories and Distribution. John Wiley & Sons, Inc., New York. pp. 412-417.

Scher, J. 2005. Federal Noxious Weed Disseminules of the U.S.. Vol. 3. Online resource at: (accessed 12 February 2008).

US Forest Service, Pacific Island Ecosystems at Risk (PIER), Ipomoea aquatica. Online resource at:  accessed [13 February 2008].

Wagner, W. L., D. R. Herbst, and D. H. Lorence. 2005-. Flora of the Hawaiian Islands website. (13 February 2008).

Wunderlin, R. P., and B. F. Hansen. 2004. Atlas of Florida Vascular Plants (http://www.plantatlas.usf.edu/).[S. M. Landry and K. N. Campbell (application development), Florida Center for Community Design and Research.] Institute for Systematic Botany, University of South Florida, Tampa.

Other Resources:

Author: Howard, V.

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.