Lemna aequinoctialis |
Lemna obscura |
|
---|---|---|
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 |
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
|
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
|
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 | ||
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) |
Web links |