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Weed Identification




Scientific Name

Lemna valdiviana

Other Common Names:

pale duckweed

Synonyms (former Scientific Names):

Lemna cyclostasa
Lemna torreyi


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.

Identifying Characteristics

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. 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.

Flower Seed Head

Very small and inconspicuous, rarely seen.

Life Cycle

summer annual

Plant Type