Lemna perpusilla
Fl. New York 2: 245. 1843.
Roots to 3.5 cm, tip usually sharp pointed; sheath narrowly winged at base (wing 2–3 times as long as wide). Stipes white, small, often decaying. Fronds floating, 1 or 2–few, coherent in groups, ovate-obovate, flat, 1–4 mm, 1–1.7 times as long as wide, margins entire; veins 3, greatest distance between lateral veins near or distal to middle; 1 distinct papilla near apex on upper surface, 2–3 very distinct papillae above node; anthocyanin absent, no reddish color; air spaces much shorter than 0.3 mm; distinct turions absent. Flowers: ovaries 1-ovulate, utricular scale open on 1 side. Fruits 0.7–1 mm, not winged. Seeds with 35–70 indistinct ribs, staying within fruit wall after ripening. 2n = 40 (U), 42 (G).
Phenology: Flowering (frequent) late spring–fall.
Habitat: Mesotrophic to eutrophic, quiet waters in temperate regions with relatively mild winters
Elevation: 0–600 m
Distribution
Que., Ark., Conn., Del., D.C., Ill., Ind., Iowa, Kans., Ky., Maine, Md., Mass., Minn., Mo., Nebr., N.J., N.Y., N.C., Ohio, Okla., Pa., R.I., Tenn., Tex., Vt., Va., W.Va., Wis.
Discussion
I know of no specimens of Lemna perpusilla from Connecticut or New Hampshire.
Selected References
None.