[3] These duckweeds were previously placed in a separate flowering plant family, the Lemnaceae, but they are now considered to be members of the Araceae.

When Lemna invades a waterway, it can be removed mechanically, by the addition of herbivorous fish (e.g. grass carp), or, inadvisedly, treated with a herbicide.

The rapid growth of duckweeds finds application in bioremediation of polluted waters, in municipal wastewater treatment [5] and as test organisms for environmental studies.

Genetic variability in responses to toxicants can occur in Lemna, and data are insufficient to recommend a specific clone for testing.

Expression constructs were engineered to cause Lemna to secrete the transformed proteins into the growth medium at high yield.

[9][10] In addition, the host Lemna can be engineered to cause secretion of proteins with human patterns of glycosylation, an improvement over conventional plant gene-expression systems.

A minimum water depth of 1 foot (30 cm) is desirable to prevent excessive temperature swings.

High nitrogen levels, for example 20 mM urea, have provided a protein content in the range of 45% by dry weight.