Lemna aequinoctialis |
Lemna minor |
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duckweed, lesser duckweed |
common duckweed, lenticule mineure, lesser duckweed, small duckweed, smaller duckweed, water lentil |
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Roots | to 3 cm; tip usually sharp pointed; sheath winged at base (wing 1–2.5 times as long as wide). |
to 15 cm, tip mostly rounded; sheath not winged. |
Flowers | ovaries 1-ovulate, utricular scale open on 1 side. |
ovaries 1-ovulate, utricular scale with narrow opening at apex. |
Fruits | 0.5–0.8 mm, not winged. |
0.8–1 mm, laterally winged toward apex. |
Seeds | with 8–26 distinct ribs, falling out of fruit wall after ripening. |
with 8–15 distinct ribs, staying within fruit wall after ripening. |
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 2–5 or more, coherent in groups, ovate, scarcely gibbous, flat, 1–8 mm, 1.3–2 times as long as wide, margins entire; veins 3(–5) (if more than 3, outer ones branching from inner ones), greatest distance between lateral veins near or proximal to middle; papillae not always distinct (one near apex usually larger); lower surface very seldom slightly reddish (much less than on upper), coloring beginning from attachment point of root, upper surface occasionally diffusely reddish; air spaces 0.3 mm or shorter; distinct turions absent. |
2n | = 40, 42, 50, 60, 80, 84. |
= 40, 42 (B), 50, 63, 126. |
Lemna aequinoctialis |
Lemna minor |
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Phenology | Flowering (frequent) spring–fall. | Flowering (rare) late spring–early fall. |
Habitat | Mesotrophic to eutrophic, quiet waters in warm-temperate to tropical regions | Mesotrophic to –eutrophic, quiet waters, in suboceanic, cool-temperate regions with relatively mild winters |
Elevation | 0–1300 mm | 0–2000 m (0–6600 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; CT; DC; DE; FL; IA; ID; IL; IN; KS; KY; LA; MA; MD; ME; MI; MN; MO; MT; NC; ND; NE; NH; NJ; NM; NY; OH; OK; OR; PA; RI; SD; TN; UT; VA; VT; WA; WI; WV; BC; ON; QC; SK; SPM; w Eurasia; Africa; Atlantic Islands [Australia (introduced), Australia; introduced, New Zealand (introduced)]
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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.) |
Indication of this species in Newfoundland (H. J. Scoggan 1978–1979) probably refers to Lemna turionifera. A specimen in the Gray Herbarium from St. Pierre and Miquelon may represent Lemna minor or L. turionifera; its determination is questionable. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 22, p. 149. | FNA vol. 22, p. 148. |
Parent taxa | Lemnaceae > Lemna | Lemnaceae > Lemna |
Sibling taxa | ||
Synonyms | L. paucicostata | |
Name authority | Welwitsch: Bol. Ann. Cons. Ultramar. (Portugal) 55: 578. (1859) | Linnaeus: Sp. Pl. 2: 970. (1753) |
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