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common duckweed, lenticule mineure, lesser duckweed, small duckweed, smaller duckweed, water lentil

duckweed, lesser duckweed

Roots

to 15 cm, tip mostly rounded;

sheath not winged.

to 3 cm;

tip usually sharp pointed;

sheath winged at base (wing 1–2.5 times as long as wide).

Flowers

ovaries 1-ovulate, utricular scale with narrow opening at apex.

ovaries 1-ovulate, utricular scale open on 1 side.

Fruits

0.8–1 mm, laterally winged toward apex.

0.5–0.8 mm, not winged.

Seeds

with 8–15 distinct ribs, staying within fruit wall after ripening.

with 8–26 distinct ribs, falling out of fruit wall after ripening.

Stipes

white, small, often decaying.

small, white, often decaying.

Fronds

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.

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.

2n

= 40, 42 (B), 50, 63, 126.

= 40, 42, 50, 60, 80, 84.

Lemna minor

Lemna aequinoctialis

Phenology Flowering (rare) late spring–early fall. Flowering (frequent) spring–fall.
Habitat Mesotrophic to –eutrophic, quiet waters, in suboceanic, cool-temperate regions with relatively mild winters Mesotrophic to eutrophic, quiet waters in warm-temperate to tropical regions
Elevation 0–2000 m (0–6600 ft) 0–1300 mm
Distribution
from FNA
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)]
[WildflowerSearch map]
[BONAP county map]
from FNA
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
[WildflowerSearch map]
[BONAP county map]
Discussion

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.)

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.)

Source FNA vol. 22, p. 148. FNA vol. 22, p. 149.
Parent taxa Lemnaceae > Lemna Lemnaceae > Lemna
Sibling taxa
L. aequinoctialis, L. gibba, L. minuta, L. obscura, L. perpusilla, L. trisulca, L. turionifera, L. valdiviana
L. gibba, L. minor, L. minuta, L. obscura, L. perpusilla, L. trisulca, L. turionifera, L. valdiviana
Synonyms L. paucicostata
Name authority Linnaeus: Sp. Pl. 2: 970. (1753) Welwitsch: Bol. Ann. Cons. Ultramar. (Portugal) 55: 578. (1859)
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