Duckweed

Common Name(s):
Common duckweed, Duckweed
Scientific Name:
Lemna spp.
Family:
Lemnaceae
Growth Traits:
Native, annual, warm season
Description: Similar to common duck’s meat, but smaller, and has only one root coming out of each frond (leaf). The fronds are green on the bottom, unlike common duck’s meat. Common duckweed can completely cover a pond and is typically found with other floating vegetation. It is common in impoundments that are protected from wind and wave action, which can prevent it from becoming very abundant. When common duckweed covers a pond for a lengthy time, the pond can experience dissolved oxygen problems that can cause a fish kill. This plant is eaten by waterfowl and also can provide habitat for invertebrates, which are eaten by fish and waterfowl.
Chemical Control Options: Fluridone, penoxsulam, flumioxazin or diquat.
Mechanical Control Options: Physically removing common duckweed is only temporarily effective because it has the ability to recover quickly. Removing timber that blocks wind to the south and north of a pond usually allows more wave action, which physically moves common duckweed off a pond and onto the shore when the bank slope is not too steep.
Biological Control Options: Grass carp or tilapia generally are only somewhat effective.