Duckweeds

Lemna spp.

Alternate names
Common Duckweeds

Weed Description
Very small floating aquatic plants that often form dense mats over large areas of the water surface. The duckweeds are free-floating and do not have stems or typical leaves.

Leaves
Flattened, round to elliptic in shape, reaching 1/8 inch long and 1/10 inch wide. Each leaf or frond has 1 root that dangles below the water surface.

Flowers
Very small and inconspicuous, rarely seen.

Identifying Characteristics
Very small floating aquatic plants with a single small root dangling below. The giant duckweeds (Spirodela spp.) are similar to these species but have 2 or more roots emerging from each frond and usually have at least one purple or red dot on the frond. Watermeal (Wolffia spp.) is also similar in appearance to the duckweeds but is generally much smaller and also does not have roots dangling below.

Office of Programs

University of Missouri

Duckweeds

Lemna spp.