Water spinach, swamp morning-glory
This plant can form a large, dense, floating mat of many intertwined stems that can shade both submerged aquatic and emergent vegetation. Small fragments of this plant can produce new plants with a fast growth rate of approximately 4 inches per day. This presents a threat to rivers, lakes and wetlands.
OverviewOther names for this plant include:
- Common names: Swamp morning-glory, kangkong, river spinach, Chinese spinach, water convolvulus
- Scientific names: Ipomoea reptans; Ipomoea subdentata; Convolvulus reptans
- Dense and tangled mats of fast-growing vegetation can obstruct water flow and access to open water.
- Water spinach can grow in a range of habitats such as lakes, ponds, wetlands and streams, shading out native plants that are important for fish and wildlife.
- The floating vegetation mats formed by water spinach can create stagnant water below that is ideal habitat for breeding mosquitoes.
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 water spinach was based upon this literature review developed by the department.
Leaves: Water spinach leaves are usually green and arrowhead or lanceolate in shape. The leaves grow alternately on the stems of the plant; 2 to 6 inches long and up to 3 inches wide.
Flowers: Typically look like “morning glory” flowers. They are trumpet-shaped and showy, white to pale pink or lilac in color and grow singly or in small groups.
Fruits & seeds: Fruits are an oval or spherical capsule, woody at maturity, 0.5 inches wide, each capsule holds 1-4 grayish seeds. The pods and seeds can easily float and travel to spread new plants.
Roots: Roots are found at the nodes of the stems. Water spinach easily forms new plants when fragments of stem break off and take root.
Stems: The stems are hollow and trailing, usually up to 3 meters (9 feet) but often much longer. The stems are herbaceous and have a milky sap. Where the plant grows on the water, the stems float in tangled mats.
Similar species: Other species of Ipomoea or Convolvulus such as field bindweed, sweet potato or morning glory have similar flowers and leaves, but lack the hollow floating stems.
Currently, there have been no reports of water spinach in Wisconsin. Have you seen it? Send us a report.
Mechanical: Not feasible to cut as the plant readily spreads from fragments. Hand pulling is one option if all fragments are collected and destroyed.
Chemical: Aquatic approved formulas of 2,4-D or glyphosate have had varying levels of success.
View Water spinach pictures in our photo gallery!