Small duckweeds are floating plants. They are commonly found in still or sluggish waters. They often form large floating mats. There are three types of Lemna occurring in Florida (Wunderlin, 2003). Small duckweed is located throughout the US; and in PR (Kartesz, 1999).
Small duckweeds are tiny (1/16 to 1/8 inch) green plants with shoe-shaped leaves. Each plant has two to several leaves joined at the base. A single root hangs beneath.
Small duckweed may be confused with giant duckweed, Spirodela polyrhiza. Compare the leaf size and root number.
For brief control information, see Efficacy of Herbicide Active Ingredients Against Aquatic Weeds by K. Langeland, M. Netherland, and W. Haller.
Also see giant duckweed, Spirodela polyrhiza
Small duckweed – Lemna valdiviana
There are 13 species of lemna in the world, four of which are in Florida. These very small duckweeds are commonly found in still or sluggish waters throughout the state. They often form large mats. Small duckweeds are tiny, green, floating plants with shoe-shaped leaves. Each plant has 2 to several leaves joined at the base. A single root hangs beneath. Lemna (small duckweeds) can be distinguished from Spirodela (giant duckweeds) by leaf shape and root number. Lemna leaves are shoe-shaped. Spirodela leaves are much larger and rounded. Lemna bears a single root on each leaf. Spirodela bears several roots on each leaf. This tiny floating plant has green, shoe-shaped leaves. Each plant has a single root.