Wolffia columbiana is a minute, free floating monocotyledon, plants without stems, leaves or roots, about 0.1 cm diameter, spherical to ellipsoid, floating low in water, light green, translucent, often found with Lemna.
Flowers rarely produced, then consisting of one stamen and one ovary, arising through upper surface of plant body.
Wetland status: OBL.
Frequency in NYC: Very infrequent.
Habitat: Still, high nutrient water. (Accessed 5/2014).