Lemna minuta
in A. von Humboldt et al., Nov. Gen. Sp. 1: 372. 1816.
Roots to 1.5 cm, tip rounded to pointed; sheath not winged. Stipes white, small, often decaying. Fronds floating, 1 or 2–few, coherent in groups, obovate, flat to thickish (but not gibbous), 0.8–4 mm, 1–2 times as long as wide, margins entire; veins 1, sometimes indistinct, very rarely longer than extension of air spaces, not longer than 2/3 of distance between node and apex; with or without small papillae along midline; anthocyanin absent; largest air spaces much shorter than 0.3 mm; turions absent. Flowers: ovaries 1-ovulate, utricular scale open on 1 side. Fruits 0.6–1 mm, not winged. Seeds with 12–15 distinct ribs. 2n = 36 (U), 40 (U), 42 (G).
Phenology: Flowering (very rare) late spring–early fall.
Habitat: Mesotrophic to eutrophic, quiet waters in temperate to subtropical regions with relatively mild winters
Elevation: 0–2600 m
Distribution
Introduced; Ala., Ariz., Ark., Calif., Colo., Fla., Ga., Ill., Ind., Kans., Ky., La., Mich., Mo., Nebr., Nev., N.Mex., Ohio, Okla., Oreg., Tenn., Tex., Utah, Wash., W.Va., Wyo., Mexico, West Indies, Central America, South America, Eurasia (introduced).
Discussion
I know of no specimens of Lemna minuta from Mississippi, but the species is to be expected there.
Selected References
None.