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duckweed, lesser duckweed

little duckweed

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.

0.5–0.7 mm, not winged.

Seeds

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

with 10–16 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, obovate, flat or gibbous, 1–3.5 mm, 1–1.5 times as long as wide, margins entire;

veins 3, greatest distance between lateral veins near middle;

very distinct papillae near apex, some smaller indistinct ones on midline of upper surface;

lower surface very often red colored (more intensely than on upper), coloring beginning at attachment point of root, lower upper surface sometimes with red spots;

air spaces shorter than 0.3 mm; distinct turions absent.

2n

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

= 40, 42, 50.

Lemna aequinoctialis

Lemna obscura

Phenology Flowering (frequent) spring–fall. Flowering (occasional) spring–fall.
Habitat Mesotrophic to eutrophic, quiet waters in warm-temperate to tropical regions Mesotrophic to –eutrophic, quiet waters, in temperate to subtropical regions with mild winters
Elevation 0–1300 mm 0–800 m (0–2600 ft)
Distribution
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]
from FNA
AL; AR; DC; DE; FL; GA; IA; IL; IN; KS; KY; LA; MD; MN; MO; MS; NC; NE; NJ; NY; OH; OK; PA; SC; SD; TN; TX; VA; WI; c Mexico; South America (Colombia, Ecuador); Hawaii
[WildflowerSearch map]
[BONAP county map]
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.)

Source FNA vol. 22, p. 149. FNA vol. 22.
Parent taxa Lemnaceae > Lemna Lemnaceae > Lemna
Sibling taxa
L. gibba, L. minor, L. minuta, L. obscura, L. perpusilla, L. trisulca, L. turionifera, L. valdiviana
L. aequinoctialis, L. gibba, L. minor, L. minuta, L. perpusilla, L. trisulca, L. turionifera, L. valdiviana
Synonyms L. paucicostata L. minor var. obscura
Name authority Welwitsch: Bol. Ann. Cons. Ultramar. (Portugal) 55: 578. (1859) (Austin) Daubs: Illinois Biological Monographs 34: 20. (1965)
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