Spirodela species are members of the Araceae under the APG II system.

[2][3] Spirodela species are free-floating plants that have their stem transformed into leaf-like structures called fronds; each plant is represented by a frond with roots, therefore they do not have leaves.

Plants are green, but may turn red due to the presence of anthocyanin.

[5] Certain species of Spirodela overwinter as turions, dormant starchy shoots[4] that lack air pockets, which sink to the bottom of the water.

Spirodela often forms floating mats with related species (e.g. Lemna and Wolffia).