Lemna aequinoctialis |
Lemna minuta |
|
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duckweed, lesser duckweed |
least duckweed |
|
Roots | to 3 cm; tip usually sharp pointed; sheath winged at base (wing 1–2.5 times as long as wide). |
to 1.5 cm, tip rounded to pointed; sheath not winged. |
Flowers | ovaries 1-ovulate, utricular scale open on 1 side. |
ovaries 1-ovulate, utricular scale open on 1 side. |
Fruits | 0.5–0.8 mm, not winged. |
0.6–1 mm, not winged. |
Seeds | with 8–26 distinct ribs, falling out of fruit wall after ripening. |
with 12–15 distinct ribs. |
Stipes | small, white, often decaying. |
white, small, often decaying. |
Fronds | floating, 1 or 2–few, coherent in groups, ovate-lanceolate, flat, 1–6 mm, 1–3 times as long as wide, margins entire; veins 3, greatest distance between lateral veins near or proximal to middle; 1 often very distinct papilla near apex on upper surface and 1 above node; anthocyanin absent, no reddish color; largest air spaces much shorter than 0.3 mm; distinct turions absent. |
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. |
2n | = 40, 42, 50, 60, 80, 84. |
= 36 (U), 40 (U), 42 (G). |
Lemna aequinoctialis |
Lemna minuta |
|
Phenology | Flowering (frequent) spring–fall. | Flowering (very rare) late spring–early fall. |
Habitat | Mesotrophic to eutrophic, quiet waters in warm-temperate to tropical regions | Mesotrophic to eutrophic, quiet waters in temperate to subtropical regions with relatively mild winters |
Elevation | 0–1300 mm | 0–2600 m (0–8500 ft) |
Distribution |
AL; AR; AZ; CA; FL; GA; IA; IL; IN; KS; KY; LA; MO; MS; NC; NE; NM; OK; SC; TN; TX; VA; WI; Central America; South America; Indian Ocean Islands; Pacific Islands; West Indies; Atlantic Islands; Africa; s Eurasia; Australia
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AL; AR; AZ; CA; CO; FL; GA; IL; IN; KS; KY; LA; MI; MO; NE; NM; NV; OH; OK; OR; TN; TX; UT; WA; WV; WY; Mexico; Central America; South America; West Indies [Introduced, Eurasia (introduced)]
|
Discussion | Some authors did not distinguish between Lemna aequinoctialis and L. perpusilla and used the latter name for both species. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
I know of no specimens of Lemna minuta from Mississippi, but the species is to be expected there. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 22, p. 149. | FNA vol. 22, p. 150. |
Parent taxa | Lemnaceae > Lemna | Lemnaceae > Lemna |
Sibling taxa | ||
Synonyms | L. paucicostata | L. minima, L. minuscula |
Name authority | Welwitsch: Bol. Ann. Cons. Ultramar. (Portugal) 55: 578. (1859) | Kunth: in A. von Humboldt et al., Nov. Gen. Sp. 1: 372. (1816) |
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