A genus (Lemna) of small plants, seen floating in great quantity on the surface of stagnant pools fresh water, and supposed to furnish food for ducks; -- called also duckmeat.

any small or minute aquatic plant of the family Lemnaceae that float on or near the surface of shallow ponds

The smallest Canoe Country perennial, Duckweed is a single leaf plant of the genera Lemna and Spirodela which floats, often in large mats, on the surface of still waters.