Lemna perpusilla minute duckweed Lemnaceae R, ml (Torrey 2017);

Lemna perpusilla plants. commons.wikimedia.org

Lemna perpusilla plants. commons.wikimedia.org (Accessed 3/2018).

Lemna perpusilla is a tiny, free-floating, aquatic herb 0.1-0.2 cm long, usually 1-2 times longer than wide, more-or-less egg-shaped (obliquely obovate) and rounded on both sides. Each body (thallus) produces a single unbranched root.

Leaves none. The body is green.

Flowers (use microscope) tiny and rarely produced. Reproduces mostly by budding.

Fruit a utricle – minute, 1-seeded, slightly inflated and thin walled.

Wetland status: OBL. 

Frequency in NYC: Very infrequent.

Origin: Native.