Lemna turionifera |
Lemna obscura |
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lenticulare turionifère, red duckweed, turion duckweed |
little duckweed |
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Roots | shorter than 15 cm, tip mostly rounded; sheath not winged. |
to 15 cm, tip mostly rounded; sheath not winged. |
Flowers | ovaries 1-ovulate, utricular scale with narrow opening at apex. |
ovaries 1-ovulate, utricular scale with narrow opening at apex. |
Fruits | 0.5–0.6 mm, not winged. |
0.5–0.7 mm, not winged. |
Seeds | with 30–60 indistinct ribs, staying within fruit wall after ripening. |
with 10–16 distinct ribs, staying within fruit wall after ripening. |
Stipes | white, small, often decaying. |
white, small, often decaying. |
Fronds | floating, 1 or 2–few, coherent in groups, obovate, scarcely gibbous, flat, 1–4 mm, 1–1.5 times as long as wide, margins entire; veins 3, greatest distance between lateral veins near or distal to above middle; papillae distinct on midline of upper surface (apical papilla scarcely larger than others); lower surface often red (more intensely so than on upper), coloring beginning at attachment point of root, upper surface (especially near apex) sometimes with red spots; air spaces to 0.3 mm; turions sometimes present, rootless, olive to brown, 0.8–1.6 mm diam., sinking to bottom. |
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 (G), 50, 80. |
= 40, 42, 50. |
Lemna turionifera |
Lemna obscura |
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Phenology | Flowering (occasional) summer. | Flowering (occasional) spring–fall. |
Habitat | Mesotrophic to –eutrophic, quiet waters, in continental, temperate regions | Mesotrophic to –eutrophic, quiet waters, in temperate to subtropical regions with mild winters |
Elevation | 0–3700 m (0–12100 ft) | 0–800 m (0–2600 ft) |
Distribution |
AK; AL; AZ; CA; CO; CT; IA; ID; IL; IN; KS; MA; MI; MN; MO; MT; ND; NE; NJ; NM; NV; NY; OH; OK; OR; PA; RI; SD; TX; UT; VT; WA; WI; WV; WY; AB; BC; MB; NB; NL; NS; NT; ON; PE; QC; SK; YT; SPM; Mexico (Baja California); Eurasia
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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
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Discussion | I know of no specimens of Lemna turionifera from Maine, New HampshireSt. Pierre and Miquelon, or from New Jersey, but the species is to be expected there.. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Source | FNA vol. 22, p. 148. | FNA vol. 22. |
Parent taxa | Lemnaceae > Lemna | Lemnaceae > Lemna |
Sibling taxa | ||
Synonyms | L. minor var. obscura | |
Name authority | Landolt: Aquatic Botany 1: 355, fig. 4g–h. (1975) | (Austin) Daubs: Illinois Biological Monographs 34: 20. (1965) |
Web links |
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