[2] Commonly called watermeal or rootless duckweed,[3][4] these aquatic plants resemble specks of cornmeal floating on the water.

Wolffia are free-floating aquatic plants with fronds that are nearly spherical to cylindrical in shape and lack airspaces or veins.

The fastest growth rate (in fact, the fastest growth rate of any flowering plant) is shown by a clone of Wolffia microscopica, with a doubling time of 29.3 hours.

One species, W. microscopica, is over 20% protein by dry weight and has high content of essential amino acids.

[6] As of 2020[update], eleven species are accepted on Kew's Plants of the World Online:[1]