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
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.