Species Overview

Native to: Southeastern Asia

Duck-lettuce is thought to have arrived in the United States via propagules transported in rice shipments. Although it is considered slow to spread and has not yet become highly invasive in the US, it has been preemptively added to the Federal Noxious Weed List due to the potential impacts should it become more widespread. It was first found in Florida in 2003 in Thompsons Bayou, a small, slow-flowing tributary of the Escambia River, it has been managed there and has not spread beyond this initial area. It has also been documented in California, Texas, Louisiana, and Missouri.

Species Characteristics

Family: Hydrocharitaceae

Habit: Annual or perennial submersed aquatic plant

Leaves: Juvenile leaves somewhat linear, becoming oblanceolate, ovate or broadly cordate with maturity (Godfrey and Wooten 1979). Largest leaves from 11 to 16 cm long, their bases tapering to meet the petioles. Petioles of varying lengths (potentially up to 50 cm). Lower margins of leaves and edges of petioles often shallowly serrated to sharply toothed (Cook and Urmi-König 1984). Conspicuous longitudinal ribbing and cross-ribbing on the upper surface of the leaves gives a quilted effect (Cook et al. 1984).

Flowers: Wrapped within spathes, cylindrical structures 2-4 cm long, composed of green bracts that are ornamented with 3 or more ruffled wings. Spathes born on long, angled stalks that become spiraled after flowering. Sepals and short-lived petals of male flowers exert from the tip of the spathe just above the water surface. Spathes containing female and/or bisexual flowers are self-fertile and remain submersed. Petals white, pink, blue or purple, often tinged with yellow at the base (Cook and Urmi-König 1984).

Fruit/Seed: Fleshy, encapsulated fruits contain as many as 2000 seeds (Cook and Urmi-König 1984).

Distribution in Florida: Escambia county

Impacts

Reproduces solely by seed. Potential impacts include inhibiting recreational activities, degrading water quality, and reducing biodiversity. It could also cause problems in rice production.

Always clean boats and equipment and drain live wells before leaving a waterbody.

Small plants can be hand pulled. It is best to conduct this management strategy before the seed is set.

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None known.

Consult your local UF IFAS Extension Office for management recommendations.